Prentice hall's federal taxation test bank chapter 4

Prentice Hall's Federal Taxation 2013 Corporations, 26e (Pope)

Chapter C4 Corporate Nonliquidating Distributions

1) Corporate distributions that exceed earnings and profits are always capital gains.

Answer: FALSE

Page Ref.: C:4-2

Objective: 3

2) Corporations may always use retained earnings as a substitute for earnings and profits.

Answer: FALSE

Page Ref.: C:4-5

Objective: 3

3) When computing E & P, Section 179 property must be expensed ratably over a five-year period, starting with the month in which it is expensed for Sec. 179 purposes.

Answer: TRUE

Page Ref.: C:4-5

Objective: 2

4) A shareholder's basis in property distributed as a dividend is its fair market value.

Answer: TRUE

Page Ref.: C:4-9

Objective: 3

5) When appreciated property is distributed in a nonliquidating distribution, the net effect on the distributing corporation's E&P is that it is reduced by the FMV of the property distributed and increased by the gain (net of federal income taxes) recognized due to the property distribution.

Answer: TRUE

Page Ref.: C:4-10

Objective: 3

6) Corporations recognize gains and losses on the distribution of property to shareholders if the property's fair market value differs from its basis.

Answer: FALSE

Page Ref.: C:4-10

Objective: 3

7) In a nontaxable distribution of stock rights, when the value of the rights is less than 15% of the value of the stock with respect to which the rights were distributed, the basis of the rights is zero unless the shareholder elects to allocate stock basis to the rights.

Answer: TRUE

Page Ref.: C:4-14 and C:4-15

Objective: 4

8) In a taxable distribution of stock, the recipient shareholder takes a basis equal to the FMV of the stock received.

Answer: TRUE

Page Ref.: C:4-15

Objective: 4

9) A stock redemption is always treated as if the shareholder sold his stock to the corporation. Answer: FALSE

Page Ref.: C:4-17

Objective: 5

10) The Sec. 318 family attribution rules can be waived for purposes of the Sec. 302(b)(3) complete termination rules even though the redeeming shareholder is a creditor of the corporation.

Answer: TRUE

Page Ref.: C:4-22

Objective: 5

11) A partial liquidation of a corporation is treated as a dividend in the case of a corporate shareholder. Answer: TRUE

Page Ref.: C:4-24 and C:4-25

Objective: 5

12) Two corporations are considered to be brother-sister corporations for purposes of the Sec. 304 redemption rules if one shareholder owns more than 50% of each corporation.

Answer: TRUE

Page Ref.: C:4-30

Objective: 7

13) Identify which of the following statements is false.

A) For E&P dividend distribution purposes, property as defined in Sec. 317(a) includes money.

B) The function of E&P is to provide a measure of a corporation's economic ability to pay dividends.

C) At formation, a corporation's E&P depends on the amount of capital contributed by the shareholders.

D) Adjustments to taxable income when computing E&P do not include tax-exempt interest. Answer: C

Page Ref.: C:4-3 and C:4-4

Objective: 2

14) Identify which of the following increases Earnings & Profits.

A) a capital contribution

B) life insurance proceeds payable to the spouse

C) tax-exempt interest income

D) All of the above increase E&P of a corporation.

Answer: C

Page Ref.: C:4-4

Objective: 2

15) Current E&P does not include

A) tax-exempt interest income.

B) life insurance proceeds where the corporation is the beneficiary.

C) federal income tax refunds from prior years.

D) All of the above are included.

Answer: D

Page Ref.: C:4-4

Objective: 2

16) Grant Corporation sells land (a noninventory item) with a basis of $57,000 for $100,000. Nichole will be paid on an installment basis in five equal annual payments, starting in the current year. The E&P for the year of sale will be increased as a result of the sale (excluding federal income taxes) by

A) $0.

B) $8,600.

C) $43,000.

D) $100,000.

Answer: C

Explanation: C) The entire gain on the installment sale must be used to increase E&P in the year of sale. Page Ref.: C:4-5; Example C:4-5

Objective: 2

17) Boxer Corporation buys equipment in January of the current year with a seven-year class life for $15,000. The corporation expensed the $15,000 under Sec. 179. The deduction in the year of purchase for E&P purposes due to the acquisition and expensing of the equipment is

A) $1,500.

B) $3,000.

C) $14,000.

D) $15,000.

Answer: B

Explanation: B) Property expensed under Sec. 179 is expensed ratably using the straight-line method over five years, commencing with the month in which it is deductible for Sec. 179 purposes when computing E&P regardless of the number of years in its class life.

$15,000/5 yrs. = $3,000

Objective: 2

18) For purposes of determining current E&P, which of the following items cannot be deducted in the year incurred?

A) charitable contribution in excess of the 10% limitation

B) capital losses in excess of capital gains

C) life insurance premiums (in excess of the increase in cash surrender value for the policy) paid on the lives of key employees

D) dividends-received deduction.

Answer: D

Page Ref.: C:4-5

Objective: 2

19) Identify which of the following statements is true.

A) Section 179 property must be expensed ratably over a five-year period when computing E&P.

B) Losses on property sales to related parties are not deductible when computing E&P.

C) Distributions made out of accumulated E&P are allocated ratably between multiple distributions made during the tax year.

D) All of the above are false.

Answer: A

Page Ref.: C:4-5 and C:4-6

Objective: 2

20) Poppy Corporation was formed three years ago. Poppy's E&P history is as follows:

Poppy Corporation's accumulated E&P on January 1 will be

A) $0.

B) $7,000.

C) $5,000.

D) $12,000.

Answer: B

Explanation: B) ($6,000 - $4,000) + ($5,000 - $1,000) + $1,000 = $7,000

Page Ref.: C:4-7

Objective: 2

21) Dixie Corporation distributes $31,000 to its sole shareholder, Sally. At the time of the distribution, Dixie's E&P is $25,000 and Sally's basis in her Dixie stock is $10,000. Sally's basis in her Dixie stock after the distribution is

A) $4,000.

B) $10,000.

C) $25,000.

D) $31,000.

Answer: A

Explanation: A) $31,000 - $25,000 = $6,000 distribution in excess of E&P. $10,000 basis - $6,000 excess distribution = $4,000.

Page Ref.: C:4-7

Objective: 3

22) Crossroads Corporation distributes $60,000 to its sole shareholder Harley. Crossroads has earnings and profits of $55,000 and Harley's basis in her stock is $20,000. After the distribution, Harley's basis is

A) $5,000.

B) $15,000.

C) $20,000.

D) $60,000.

Answer: B

Explanation: B) $55,000 of the distribution reduces E&P to $0, and $5,000 is a reduction in the basis of Harley's stock.

Page Ref.: C:4-7

Objective: 3

23) Tomika Corporation has current and accumulated earnings and profits of $0. Tomika distributes $10,000 to its sole shareholder, Alana. What are Tomika's earnings and profits after the distribution?

A) $0

B) ($10,000)

C) $10,000

D) none of the above

Answer: A

Explanation: A) Distributions cannot create an E&P deficit.

Page Ref.: C:4-7

Objective: 2

24) Exit Corporation has accumulated E&P of $24,000 at the beginning of the current tax year. Current

E&P is $20,000. During the year, the corporation makes the following distributions to its sole shareholder who has a $22,000 basis for her stock.

The treatment of the $15,000 August 1 distribution would be

A) $15,000 is taxable as a dividend; $5,000 from current E&P and the balance from accumulated E&P.

B) $15,000 is taxable as a dividend from accumulated E&P.

C) $4,000 is taxable as a dividend from accumulated E&P, and $11,000 is tax-free as a return of capital.

D) $5,000 is taxable as a dividend from current E&P, and $10,000 is tax-free as a return of capital. Answer: D

Page Ref.: C:4-7

Objective: 3

25) Oreo Corporation has accumulated E&P of $8,000 at the beginning of the current year. During the year (a nonleap year), the corporation incurs a current E&P deficit of $18,250. The corporation distributes $11,000 on March 20th to Morris, its sole shareholder, who has a $9,000 basis for his stock. If the exact loss cannot be determined as of the date of distribution, the treatment of the distribution will be

A) $4,100 dividend and a $6,900 capital gain.

B) $11,000 return of capital.

C) $4,100 dividend and a $6,900 tax free return of capital.

D) $8,000 dividend and a $3,000 return of capital.

Answer: C

Explanation: C) 31 + 28 + 19 = 78; 78/365 × $18,250 = $3,900 reduction in accumulated E&P.

$8,000 - $3,900 loss accrued to distribution date = $4,100 E&P available for distribution. $6,900 ($11,000 - $4,100) balance of the distribution is a return of capital.

Page Ref.: C:4-8; Example C:4-13

Objective: 3

26) Identify which of the following statements is true.

A) If both the current and accumulated E&P have deficit balances, a corporate distribution cannot be characterized as a dividend.

B) The shareholder's basis in property received in a nonliquidating distribution is the property's FMV reduced by liabilities assumed by the shareholder.

C) A corporation recognizes gain when distributing money as a dividend to its shareholders.

D) All of the above are false.

Answer: A

Page Ref.: C:4-8 through C:4-9

Objective: 3

27) Identify which of the following statements is true.

A) The holding period for property received by a shareholder in a nonliquidating distribution begins on the day after the distribution.

B) When making a nonliquidating distribution, a corporation recognizes gains and losses.

C) When making a nonliquidating distribution, the corporation's E&P is reduced by the property's FMV even though the property's basis is greater than its FMV.

D) All of the above are false.

Answer: A

Page Ref.: C:4-9

Objective: 3

28) Hogg Corporation distributes $30,000 to its sole shareholder, Ima. At the time of the distribution, Hogg's E&P is $14,000 and Ima's basis in her stock is $10,000. Ima's gain from this transaction is a

A) $6,000 capital gain.

B) $14,000 capital gain.

C) $20,000 capital gain.

D) $30,000 capital gain.

Answer: A

Explanation: A) $30,000 distribution - $14,000 E&P(dividend) - $10,000 return of capital = $6,000

Page Ref.: C:4-9

Objective: 3

29) One consequence of a property distribution by a corporation to a shareholder is that

A) the amount of the distribution is increased by any liability assumed by the shareholder.

B) the holding period of the distributed property includes the holding period of the distributing corporation.

C) the shareholder's basis in the distributed property is the same as the distributing corporation's basis.

D) any liabilities assumed by the shareholder do not reduce the shareholder's basis.

Answer: D

Page Ref.: C:4-9

Objective: 3

30) Wills Corporation, which has accumulated a current E&P totaling $65,000, distributes land to its sole shareholder, an individual. The land has an FMV of $75,000 and an adjusted basis of $55,000. The shareholder assumes a $15,000 liability associated with the land. The shareholder will recognize

A) $60,000 of dividend income and have a $60,000 basis in the land.

B) $65,000 of dividend income and have a $75,000 basis in the land.

C) $60,000 of dividend income and have a $75,000 basis in the land.

D) $65,000 of dividend income and have a $65,000 basis in the land.

Answer: C

Explanation: C) Dividend equals $75,000 FMV - $15,000 liability assumed = $60,000. Basis equals the $75,000 FMV of the property.

Page Ref.: C:4-9; Example C:4-14

Objective: 3

31) Wills Corporation, which has accumulated a current E&P totaling $70,000, distributes land to its sole shareholder, an individual. The land has an FMV of $75,000 and an adjusted basis of $60,000. The shareholder assumes a $15,000 liability associated with the land. The transaction will have the following tax consequences.

A) The corporation will recognize a $15,000 gain; the shareholder will recognize dividend income of $75,000.

B) The corporation will recognize no gain; the shareholder will recognize dividend income of $75,000.

C) The corporation will recognize a $15,000 gain; the shareholder will recognize dividend income of $60,000.

D) The corporation will recognize no gain; the shareholder will recognize dividend income of $60,000. Answer: C

Explanation: C) The corporation will recognize $15,000 ($75,000 FMV - $60,000 basis) of gain as if it had sold the property immediately preceding the distribution. The shareholder has dividend income equal to the $75,000 FMV minus the $15,000 of liabilities assumed, or $60,000, (but not in excess of the E&P). Page Ref.: C:4-10

Objective: 3

32) A corporation distributes land and the related liability to Meg, its sole shareholder. The land has an FMV of $60,000 and is subject to a liability of $70,000. The corporation has current and accumulated E&P of $80,000. The corporation's adjusted basis for the property is $70,000. What effect does the transaction have on the corporation?

A) A recognized loss of $10,000; its E&P is reduced by $70,000.

B) A recognized loss of $10,000; its E&P is unchanged.

C) No recognized gain or loss; its E&P is reduced by $60,000.

D) No recognized gain or loss; its E&P is unchanged by the distribution.

Answer: D

Page Ref.: C:4-10; Example C:4-15

Objective: 3

33) A corporation distributes land and the related liability in a nonliquidating distribution to a shareholder. The land (a capital asset) has an adjusted basis of $70,000, an FMV of $100,000 and is subject to a mortgage of $120,000. The corporation must recognize

A) a $20,000 capital loss.

B) a $50,000 capital gain.

C) a $70,000 capital gain.

D) no gain or loss.

Answer: B

Explanation: B) The property's FMV is deemed to be at least equal to the liability assumed or acquired (Sec. 311(b)). Therefore a $50,000 capital gain ($120,000 liability - $70,000 basis) is recognized.

Page Ref.: C:4-10

Objective: 3

34) Identify which of the following statements is true.

A) The FMV of an obligation is used to determine the E&P reduction when a corporation distributes the obligation to its shareholders.

B) When appreciated property is distributed to shareholders, E&P must be increased by any gain (net of taxes) recognized due to the property distribution.

C) When appreciated property is distributed in a nonliquidating distribution, the net effect on the distributing corporation's E&P is that it is reduced by the net of the FMV of the property distributed minus the gain (net of federal income taxes) recognized due to the property distribution.

D) Only B and C above are true.

Answer: D

Page Ref.: C:4-10

Objective: 3

35) Which of the following transactions does not have the potential of creating a constructive dividend?

A) compensation paid by a corporation to a shareholder-employee

B) purchase of corporate property by the shareholder

C) shareholder's rental of corporate property

D) All of the above can result in a constructive dividend.

Answer: D

Page Ref.: C:4-11 through C:4-13

Objective: 3

36) Identify which of the following statements is true.

A) Loans made to shareholders in proportion to their stock ownership in the corporation is evidence that the loans are disguised dividends.

B) Corporate payments for the shareholder's benefit may be a taxable dividend.

C) If the shareholder can elect to receive distributing corporation stock or money, the receipt of distributing corporation stock will be a taxable dividend.

D) All of the above are true.

Answer: D

Page Ref.: C:4-12 through C:4-14

Objective: 7

37) An individual shareholder owns 3,000 shares of Baxter Corporation common stock with a basis of $10 per share. She receives a nontaxable 5% stock dividend. The basis per share of the common stock after the stock dividend is

A) $9.00.

B) $9.50.

C) $9.52.

D) $10.00.

Answer: C

Explanation: C) $30,000/[3,000 shares + (0.05 × 3,000 shares)] = $9.52

Page Ref.: C:4-14

Objective: 4

38) Tia owns 2,000 shares of Bass Corporation common stock with an $80,000 basis. Bass distributes a nontaxable preferred stock dividend. When the preferred stock is distributed, it has an FMV of $60,000 and the FMV of the 2,000 common stock shares is $180,000. The basis of the preferred stock is

A) $0.

B) $20,000.

C) $60,000.

D) $80,000.

Answer: B

Explanation: B) [$60,000 (FMV)/$240,000 (total FMV)] × $80,000 (basis) = $20,000. Basis is allocated based on relative FMVs.

Page Ref.: C:4-14; Example C:4-20

Objective: 4

39) Bat Corporation distributes stock rights with a $20,000 FMV to its common stock shareholders. The $20,000 value of the stock rights at the time of distribution is less than 15% of the value of the underlying stock. Which of the following statements is true?

A) A shareholder must allocate basis to the rights based on the relative FMVs of the stock and the rights.

B) A shareholder cannot allocate any basis to the rights.

C) The basis in the rights is zero unless a shareholder makes a valid election to allocate basis to the rights.

D) The holding period for the rights begins on the day the rights are distributed in all cases.

Answer: C

Page Ref.: C:4-15; Example C:4-21

Objective: 4

40) Identify which of the following statements is false.

A) The distribution of stock rights will be taxable if the value of the stock rights is more than 15% of the value of the underlying stock.

B) The distribution of stock rights is generally tax free under Sec. 305.

C) If the value of stock rights is less than 15% of the value of the underlying stock, the basis of the rights is zero unless the shareholder elects to allocate basis to the rights.

D) The holding period for stock rights includes the holding period for the underlying stock.

Answer: A

Page Ref.: C:4-15

Objective: 4

41) Bruce receives 20 stock rights in a nontaxable distribution. The stock rights have an FMV of $5,000. The common stock with respect to which the rights are issued has a basis of $4,000 and an FMV of $120,000. Bruce allows the stock rights to lapse. He can deduct a loss of

A) $0.

B) $1,000.

C) $5,000.

D) none of the above

Answer: A

Page Ref.: C:4-15; Example C:4-23

Objective: 4

42) Identify which of the following statements is true.

A) The distributing corporation's E&P must be reduced by the FMV of nontaxable stock rights distributed to shareholders.

B) A stock redemption can be used to withdraw some assets from a corporation prior to a sale of the business.

C) A shareholder can redeem part of his stock and recognize a capital gain if the corporation has only one shareholder.

D) All of the above are false.

Answer: B

Page Ref.: C:4-16

Objective: 5

43) Which of the following is not a reason for a stock redemption?

A) desire by remaining shareholders to retain control

B) desire by shareholders to reduce the corporate tax liability

C) Redemption of shares is a good corporate investment.

D) No outside market exists for the stock.

Answer: B

Page Ref.: C:4-16

Objective: 5

44) Elijah owns 20% of Park Corporation's single class of stock. Elijah's basis in the stock is $8,000. Park's E&P is $28,000. If Park redeems all of Elijah's stock for $48,000, Elijah must report dividend income of

A) $0.

B) $28,000.

C) $40,000.

D) $48,000.

Answer: A

Explanation: A) The redemption will be treated as a complete termination under Sec.302(b)(3).

Page Ref.: C:4-17; Example C:4-25

Objective: 5

45) Joshua owns 100% of Steeler Corporation's stock. Joshua's basis in the stock is $8,000. Steeler Corporation has E&P of $40,000. If Steeler Corporation redeems 60% of Joshua's stock for $50,000, Joshua must report dividend income of

A) $0.

B) $8,000.

C) $40,000.

D) $50,000.

Answer: C

Explanation: C) The entire amount of the distribution is dividend income to the extent of E&P. Here,

E&P of $40,000 is the maximum dividend distribution. The remaining $10,000 of the distribution reduces the basis of his stock to zero, and causes a $2,000 capital gain to be recognized.

Page Ref.: C:4-17; Example C:4-24

Objective: 5

46) Which of the following is not a condition that permits a stock redemption to be treated as a sale?

A) It provides funds for payment of income taxes.

B) It is not essentially equivalent to a dividend.

C) The redemption is substantially disproportionate.

D) The redemption completely terminates the shareholder's interest.

Answer: A

Page Ref.: C:4-17

Objective: 5

47) Identify which of the following statements is false.

A) A stock redemption is treated as a sale or exchange only if the shareholder's ownership of one particular class of stock is terminated.

B) An individual is not considered to own stock owned by a brother under the family attribution rules of Sec. 318.

C) An individual is considered to own the stock owned by his parents, children, spouse, and grandchildren under the family attribution rules of Sec. 318.

D) A person who has an option to purchase stock is considered to own the stock.

Answer: A

Page Ref.: C:4-17 through C:4-20

Objective: 5

48) What are the consequences of a stock redemption to the distributing corporation?

A) The corporation recognizes a gain or loss as if it had sold the distributed property for its FMV immediately before the redemption.

B) If the redemption is treated as a dividend, E&P is reduced in the same manner as for a regular dividend.

C) If the redemption is treated as a sale, only accumulated earnings and profits is reduced.

D) All of the above are correct.

Answer: B

Page Ref.: C:4-18

Objective: 5

49) Identify which of the following statements is true.

A) Generally in a stock redemption, if the shareholder's ownership percentage is substantially reduced, the redemption is treated as a sale.

B) The family attribution rules of Sec. 318 are as inclusive as the family attribution rules of Sec. 267.

C) A 10% shareholder of a corporation is considered to own 10% of any stock that is owned by the corporation under the Sec. 318 attribution rules.

D) All of the above are false.

Answer: A

Page Ref.: C:4-19

Objective: 5

50) Which of the following requirements must be met for a redemption to be treated as substantially disproportionate?

A) The shareholder must own less than 50% of the outstanding stock (in terms of voting power) after the redemption.

B) After the redemption, the shareholder must own less than 80% of his percentage ownership of voting stock prior to the redemption.

C) After the redemption, the shareholder must own less than 80% of his percentage ownership of common stock (voting and nonvoting) prior to the redemption.

D) All of the above must be met.

Answer: D

Page Ref.: C:4-20

Objective: 5

51) Identify which of the following statements is true.

A) Stock ownership attributed to a corporation from one of its shareholders cannot be attributed to another of the corporation's shareholders under the Sec. 318 attribution rules.

B) Under the attribution rules relating to stock redemptions, a person who has an option to purchase stock is considered to own the stock.

C) A stock redemption that qualifies as substantially disproportionate is a safe harbor for capital gain treatment.

D) All of the above are true.

Answer: D

Page Ref.: C:4-20 and C:4-21

Objective: 5

52) Identify which of the following statements is true.

A) The Sec. 318 family attribution rules can be waived for purposes of the Sec. 302(b)(3) complete termination rules even though the redeeming shareholder is a creditor of the corporation.

B) Waiver of the Sec. 318 family attribution rules is permitted for all related party stock transactions.

C) For a redemption to be essentially equivalent to a dividend, the shareholder must not have control of the corporation immediately following the redemption.

D) All of the above are false.

Answer: A

Page Ref.: C:4-22

Objective: 5

53) Family Corporation, a corporation controlled by Buddy's family, redeems all of Buddy's stock. For the redemption to be treated as a sale, which one of the following conditions must be met?

A) Buddy cannot be a creditor of the corporation after the redemption.

B) Buddy cannot be an officer of the corporation after the redemption.

C) Buddy cannot acquire an interest, even by inheritance, for 10 years unless the bequest was made prior to the redemption.

D) Buddy must have purchased the redeemed stock from a person whose stock ownership would be attributed to Buddy.

Answer: B

Page Ref.: C:4-22

Objective: 5

54) All of Sphere Corporation's single class of stock is owned by four unrelated individuals in the following manner: Zack 27%, Xu 24.33%, Yvonne 24.33%, and Win 24.33%. Some of Zack's stock holdings are redeemed by Sphere Corporation, resulting in Zack's interest being reduced to 22.27%. Xu, Yvonne, and Win owned equally the remaining 77.73% of the Sphere stock. How should the redemption of Zack's stock be treated by Zack?

A) dividend income

B) sale transaction

C) return of capital

D) some other treatment

Answer: B

Page Ref.: C:4-23; Example C:4-35

Objective: 5

55) Identify which of the following statements is true.

A) To have a bona fide partial liquidation, a firm must continue to conduct a qualified trade or business, which it had conducted for a period of more than three years prior to the redemption.

B) To qualify as a partial liquidation, a distribution must result in a bona fide contraction of the corporate business at the corporate level.

C) A partial liquidation of a corporation must be pro rata.

D) All of the above are false.

Answer: B

Page Ref.: C:4-24

Objective: 5

56) Blast Corporation manufactures purses and make-up kits. The corporation decides to quit manufacturing purses and distributes the assets associated with this division to its shareholders. The distribution of the these assets will be treated as a partial liquidation if

A) the corporation so elects.

B) the corporation discontinues the line of business and the transaction is "essentially equivalent to a dividend."

C) the distribution is made within 24 months of the adoption of a plan of liquidation and the transaction is "not essentially equivalent to a dividend."

D) the distribution is "not essentially equivalent to a dividend" and is made within the year a plan of liquidation is adopted or within the succeeding year.

Answer: D

Page Ref.: C:4-24

Objective: 5

57) Perch Corporation has made paint and paint brushes for the past ten years. Perch Corporation is owned equally by Arnold, an individual, and Acorn Corporation. Perch Corporation has $100,000 of accumulated and current E&P. Both Arnold and Acorn Corporation have a basis in their stock of $10,000. Perch Corporation discontinues the paint brush operation and distributes assets worth $10,000 each to Arnold and Acorn Corporation in redemption of 20% of their stock. Due to the distribution, Arnold and Acorn Corporation must report:

Answer: B

Explanation: B) Acorn Corporation is a corporate shareholder and not eligible for the partially liquidating distributions to be treated as a sale since the distribution is pro rata. Arnold is eligible for sale treatment under the Sec. 302(b)(4) partial liquidation rules.

Page Ref.: C:4-24; Example C:4-37

Objective: 5

58) The gross estate of a decedent contains $2,000,000 cash and 100% of Davis Corporation stock worth $600,000. Funeral and administrative expenses and state death taxes allowable as estate tax deductions amount to $400,000. The estate owes no other liabilities. The decedent's Davis stock can be

A) redeemed to the extent of the death taxes and the estate's funeral and administrative costs with sale or exchange treatment.

B) redeemed with dividend treatment.

C) redeemed in full with sale or exchange treatment only if the proceeds are used to pay the death taxes and funeral and administrative costs.

D) redeemed to the extent of the death taxes and the funeral and administrative costs with sale or exchange treatment only if the proceeds are used to pay the death taxes and funeral and administrative costs.

Answer: B

Explanation: B) The FMV of the stock does not meet the 35% of the adjusted gross estate minimum [($2,000,000 + $600,000 - $400,000) × 0.35 = $770,000].

Page Ref.: C:4-25; Example C:4-38

Objective: 5

59) Identify which of the following statements is true.

A) If a stock redemption is made by an estate following the decedent's death, the redemption may receive capital gains treatment only if the money is actually used to pay the death taxes.

B) Attribution rules do not apply to qualified Sec. 303 stock redemptions.

C) The value of decedent's stock satisfies the Sec. 303 minimum if it is less than 35% of the decedent's gross estate.

D) All of the above are false.

Answer: B

Page Ref.: C:4-25

Objective: 5

60) Identify which of the following statements is true.

A) Only stock included in the decedent's gross estate can be redeemed under the Sec. 303 provisions.

B) If the stock redemption proceeds are used to pay either the estate's funeral and administrative expenses or death taxes, the redemption can qualify for capital gains treatment under Sec. 303.

C) Usually, a stock redemption qualifying under Sec. 303 as a redemption to pay death taxes will result in little or no gain to the redeeming shareholder.

D) All of the above are true.

Answer: D

Page Ref.: C:4-25

Objective: 5

61) Jack Corporation redeems 200 shares of its stock for $100,000 from Junior, who inherited the stock from his father, Ken. The stock's FMV on Ken's date of death was $90,000. Ken's basis in the stock was $40,000. Jack Corporation had an E&P balance of $300,000. If the redemption qualifies under Sec. 303, Junior will

A) recognize a capital gain of $10,000.

B) recognize a capital gain of $60,000.

C) recognize $100,000 in dividend income.

D) recognize dividend income of $50,000 and a capital gain of $10,000.

Answer: A

Page Ref.: C:4-26; Example C:4-41

Objective: 5

62) Identify which of the following statements is false.

A) The rules for the recognition of a gain or loss by a corporation that distributes property in redemption of its stock are the same as the rules for property distributions that are not in redemption of stock.

B) Generally, little or no gain is recognized by the redeeming shareholder in a qualified Sec. 303 redemption.

C) When a stock redemption is considered a sale of stock by the shareholder, the E&P of the redeeming corporation is reduced by the FMV of the property used to redeem the stock.

D) Under Sec. 311, a corporation does not recognize a loss when it distributes property that has declined in value.

Answer: C

Page Ref.: C:4-27

Objective: 5

63) Circle Corporation has 1,000 shares of common stock outstanding. Circle redeems 450 shares owned by Dennis for $75,000 in complete redemption of Dennis's interest. The redemption qualifies as a sale. When the redemption is made, Circle Corporation has $150,000 of current and accumulated E&P and paid-in capital of $50,000. The distribution reduces paid-in capital by

A) $67,500.

B) $22,500.

C) $17,500.

D) $0.

Answer: C

Explanation: C) 1$150,000 × 0.45 = $67,500 E&P reduction, leaving $17,500 to reduce paid-in capital. The distribution first reduces E&P by the percentage reduction in stock ownership; the balance reduces paid-in capital.

Page Ref.: C:4-27; Example C:4-42

Objective: 5

64) Identify which of the following statements is true.

A) The distribution of preferred stock as a stock dividend will result in income or a taxable gain being recognized by the shareholder on the date of the distribution if the stock is Sec. 306 stock.

B) Corporations without E&P can distribute preferred stock as a stock dividend that is Sec. 306 stock.

C) Two corporations are considered to be brother-sister corporations for purposes of the Sec. 304 redemption rules if one shareholder owns more than 50% of each corporation.

D) All of the above are false.

Answer: C

Page Ref.: C:4-30

Objective: 6

65) John owns 70% of the May Corporation stock and 60% of the June Corporation stock. John sells one-half of his interest in May Corporation to June Corporation for $45,000. The E&P accounts of May and June are $25,000 and $35,000, respectively. The result would be that

A) John has sold his stock and reports a capital gain or loss.

B) John has sold his stock and reports a capital gain but no loss.

C) the transaction is treated as a contribution to May's capital and a redemption of June stock.

D) the sale is recast as a dividend paid to John, first by June and then by May.

Answer: D

Page Ref.: C:4-30 and C:4-31

Objective: 7

66) Boris owns 60 of the 100 shares outstanding of Bread Corporation stock and 80 of the 100 shares of Butter Corporation stock. His basis in the Bread shares is $10,000 and his basis in his Butter shares is $5,000. Boris sells 30 of his Bread Corporation shares to Butter Corporation for $25,000. Bread Corporation has E&P of $20,000 and Butter Corporation has E&P of $40,000. In applying the substantially disproportionate test to determine if this is a sale or a dividend, Boris is treated as owning how many shares of Bread after the sale?

A) 30 shares

B) 54 shares

C) 60 shares

D) 80 shares

Answer: B

Explanation: B) Boris owned 60 shares and sold 30. Since he owns 80% of the corporation that acquired the 30 shares, he is treated as owning 80% of their 30, or 24 shares. He owns in total 54 [(60 - 30) + 24] shares.

Page Ref.: C:4-31; Example C:4-45

Objective: 7

67) Rose has a $20,000 basis in the 60% of the Parent Corporation stock that she owns. Parent Corporation owns a 70% interest in Child Corporation. Parent and Child have current and accumulated E&P balances of $25,000 and $40,000, respectively. In return for $15,000, Rose sells 10% of the Parent Corporation stock to Child Corporation. What is the impact of the transaction on Rose?

A) Rose will recognize a $5,000 capital gain.

B) Rose will be treated as having received a $15,000 dividend distribution from Child Corporation.

C) Rose will be treated as having sold stock to Parent Corporation and recognize a $15,000 capital gain.

D) Rose will be treated as having received a $15,000 dividend from Parent Corporation.

Answer: B

Page Ref.: C:4-32

Objective: 7

68) Which of the following statements is not true about redemptions?

A) Redemptions of Sec. 306 stock are generally treated as dividends to the shareholder.

B) A sale of stock from one controlled corporation to another controlled corporation is treated as a redemption.

C) Redemptions to pay death taxes are treated as dividends to the shareholder.

D) A distribution in redemption of stock is generally a dividend.

Answer: C

Page Ref.: C:4-33

Objective: 7

69) Marie owns one-half of the stock of Starke Corporation and serves as its President. The remaining stock is owned by 10 investors, none of whom owns more than 10% of the outstanding shares. Marie entered a hedge agreement with the corporation three years ago about salary payments that are declared unreasonable compensation by the IRS. Two years ago, the Corporation paid Marie a salary and bonus of $500,000. The IRS subsequently held that $200,000 of the salary is unreasonable compensation. Last year, Starke Corporation and the IRS agreed that $150,000 of the compensation is, in fact, unreasonable. This year, the $150,000 is repaid by Marie to the corporation.

A) The entire $500,000 is taxable to Marie in the year of receipt and $150,000 of the compensation is deductible by Marie last year.

B) Marie must amend the return of two years ago to adjust her taxable compensation to the agreed- upon reasonable amount.

C) The entire $500,000 is taxable to Marie in the year of receipt and $150,000 of the compensation is deductible by Marie this year.

D) Marie must not include the agreed-upon amount in her return since it is not deductible.

Answer: C

Page Ref.: C:4-34; Example C:4-49

Objective: 7

70) Van owns all 1,000 shares of Valley Metal Corporation stock. The stock has a $100,000 FMV. Karen wants to purchase the stock from Van but has only $70,000. Valley Metal has ample cash, which is not needed for operations. Which of the following best qualifies for bootstrap redemption treatment and no constructive dividends to the purchaser?

A) Karen contracts to acquire all the stock of the corporation on an installment plan and then uses corporate funds to pay the installment obligations.

B) Karen buys 70 shares from Van for $70,000 and Van causes Valley Metal Corporation to redeem his remaining shares for $30,000.

C) Karen buys 70 shares from Van for $70,000 and then contracts to buy the remaining 30 shares from Van. She then causes Valley Metal Corporation to redeem Van's 30 shares.

D) Karen buys 70 shares from Van for $70,000 and obtains an option to purchase Van's remaining stock for $50,000. Karen then assigns the option to Valley Metal Corporation. The corporation subsequently exercises the option.

Answer: B

Page Ref.: C:4-34; Example C:4-50

Objective: 7

71) Which of the following statements best describes a bootstrap acquisition?

A) The shareholder sells part of his or her stock to a purchaser and then the corporation redeems the original shareholder's remaining stock.

B) The shareholder sells his stock in exchange for cash and debt.

C) The shareholder exchanges his stock for stock of a different corporation.

D) none of the above

Answer: A

Page Ref.: C:4-34

Objective: 7

72) Good Times Corporation has a $60,000 accumulated E&P balance at the beginning of the year and incurs a $100,000 deficit during the year. Because of its poor operating performance, Good Times pays only three of its usual $10,000 quarterly dividend payments to its sole shareholder: those ordinarily paid March 31, June 30, and September 30. How are the March 31, June 30, and September 30 payments of $10,000 treated?

A) dividend; dividend; return of capital

B) dividend; return of capital; return of capital

C) return of capital; dividend; dividend

D) return of capital; return of capital; dividend

Answer: B

Page Ref.: C:4-35; Example C:4-52

Objective: 7

霍尔电流传感器的应用场合

霍尔电流传感器的应用场合 1、继电保护与测量：在工业应用中，来自高压三相输电线路电流互感器的二次电流，如分别经三只霍尔电流传感器，按比例转换成毫伏电压输出，然后再经运算放大器放大及有源滤波，得到符合要求的电压信号，可送微机进行测量或处理。在这里使用霍尔电流传感器可以很方便地实现了无畸变、无延时的信号转换。 2、在直流自动控制调速系统中的应用：在直流自动控制调速系统中，用霍尔电流电压传感器可以直接代替电流互感器，不仅动态响应好，还可实现对转子电流的最佳控制以及对晶闸管进行过载保护。 3、在逆变器中的应用：在逆变器中，用霍尔电流传感器可进行接地故障检测、直接侧和交流侧的模拟量传感，以保证逆变器能安全工作。 4、在不间断电源中的应用：在该应用中，用霍尔电流传感器进行控制，保证逆变电源正常工作。使用霍尔电流传感器1发出信号并进行反馈，以控制晶闸管的触发角，霍尔电流传感器2发出的信号控制逆变器，霍尔电流传感器3控制浮充电源。由于其响应速度快，霍尔电流传感器特别适用于计算机中的不间断电源。 5、在电子点焊机中的应用：在电子点焊机电源中，霍尔电流传感器起测量和控制作用。它的快速响应能再现电流、电压波形，将它们反馈到可控整流器A、B，可控制其输出。用斩波器给直流迭加上一个交流，可更精确地控制电流。用霍尔电流传感器进行电流检测，既可测量电流的真正瞬时值，又不致引入损耗。 6、用于电车斩波器的控制：电车中的调速是由调整电压实现的。而将霍尔电流传感器和其它元件配合使用，并将传感器的所有信号输入控制系统，可确保电车正常工作。 7、在交流变频调速电机中的应用：用变频器来对交流电机实施调速，在世界各发达国家已普遍使用，且有取代直流调速的趋势。用变频器控制电机实现调速，可节省10％以上的电能。在变频器中，霍尔电流传感器的主要作用是保护昂贵的大功率晶体管。由于霍尔电流传感器的响应时间往往小于5μs，因此，出现过载短路时，在晶全管未达到极限温度之前即可切断电源，使晶体管得到可靠的保护。 8、用于电能管理：霍尔电流传感器，可安装到配电线路上进行负载管理。霍尔电流传感器的输出和计算机连接起来，对用电情况进行监控，若发现过载，便及时使受控的线路断开，保证用电设备的安全。用这种装置，也可进行负载分配及电网的遥控、遥测和巡检等。

密度表观密度体积密度和堆积密度

密度、表观密度、体积密度和堆积密度 密度是指材料在绝对密实状态下单位体积的质量。表观密度是材料在包括闭口孔隙条件下单位体积的质量。体积密度是指材料在自然状态下的体积，包括材料实体及其开口与闭口孔隙条件下的单位体积的质量。堆积密度是指散粒或纤维状材料在堆积状态下单位体积的质量。密度、表观密度、体积密度和堆积密度既有联系又有差别。 材料的孔隙率是指材料内部孔隙的体积占材料总体积的百分率。空隙率则是指散粒状材料在堆积体积状态下颗粒固体物质间空隙体积(开口孔隙与间隙之和)占堆积体积的百分率。材料的孔隙有闭口和开口，其特征状态对材料的性质有重要影响。 材料内部孔隙示意 密度 密度是指材料在绝对密实状态下单位体积的质量。按下式计算： 式中ρ——材料的密度，g/cm3； m——材料的质量（干燥至恒重），g； V——材料在绝对密实状态下的体积，cm3。 除了钢材，玻璃等少数材料外，绝大多数材料内部都有一些孔隙。在测定有孔隙材料（如砖、石等）的密度时，应把材料磨成细粉，干燥后，用李氏瓶测定其绝对密实体积。材料磨得越细，测得的密实体积数值就越精确。 另外，工程上还经常用到比重的概念，比重又称相对密度，是用材料的质量与同体积水（4℃）的质量的比值表示，无单位，其值与材料密度相同（g/cm3）。 表观密度 表观密度是指单位体积（含材料实体及闭口孔隙体积）物质颗粒的干质量，也称

视密度。按下式计算： 式中ρ′——材料的表观密度，kg/m3或g/cm3； m——材料的质量，kg或g； V′——材料在包含闭口孔隙条件下的体积（即只含内部闭口孔，不含开口孔），见图1-2，m3或cm3。 通常，材料在包含闭口孔隙条件下的体积式采用排液置换法或水中称重法测量。 体积密度 体积密度是指材料在自然状态下单位体积（包括材料实体及其开口孔隙、闭口孔隙）的质量，俗称容重。体积密度可按下式计算： 式中ρ0——材料的体积密度，kg/m3或g/cm3； m——材料的质量，kg或g； V0——材料在自然状态下的体积，包括材料实体及其开口孔隙、闭口孔隙，见图1－1，m3或cm3。 对于规则形状材料的体积，可用量具测得。如加气混凝土砌块的体积是逐块量取长、宽、高三个方向的轴线尺寸，计算其体积。对于不规则形状材料的体积，可

材料的密度、表观密度与堆积密度

表示材料物理状态特征的性质 1、体积密度：材料在自然状态下单位体积的质量称为体积密度。 2、密度：材料在绝对密实状态下单位体积的质量称为密度。 3、堆积密度：散粒材料在规定装填条件下单位体积的质量称为堆积密度。 注意：密实状态下的体积是指构成材料的固体物质本身的体积；自然状态下的体积是指固体物质的体积与全部孔隙体积之和；堆积体积是指自然状态下的体积与颗粒之间的空隙之和。 4、表观密度：材料的质量与表观体积之比。表观体积是实体积加闭口孔隙体积，此体积即材料排开水的体积。 5、孔隙率：材料中孔隙体积与材料在自然状态下的体积之比的百分率。 6、开口孔隙率：材料中能被水饱和（即被水所充满）的孔隙体积与材料在自然状态下的体积之比的百分率。 7、闭口孔隙率：材料中闭口孔隙的体积与材料在自然状态下的体积之比的百分率。即闭口孔隙率=孔隙率-开口孔隙率。 8、空隙率：散粒材料在自然堆积状态下，其中的空隙体积与散粒材料在自然状态下的体积之比的百分率。 什么是绝对密实状态 悬赏分：20 - 提问时间2009-8-25 20:25问题为何被关闭 建筑材料课程中有“绝对密实状态”一词，绝对密实状态是什么意思啊？ 说的细一点哦！ 提问者：秦瀛 - 四级答复共 1 条 理想状态，无孔隙的。玻璃一类的可以理想地看做绝对密实。 绝对密实状态下的体积是指不包括孔隙在内的体积，材料在自然状态下的体积减去材料内部孔隙的体积。 测量密度时，由于一般材料的内部均含有一些孔隙，为了获得绝对密实状态的试样，须将材料磨成细粉以排除其内部孔隙，再用排液置换法求出材料的绝对密实体积。 材料的密实度是指材料在绝对密实状态下的体积与在自然状态下的体积之比。凡是内部有孔隙的材料，其密实度都小于1.材料的密实度反映固体材料中固体物质的充实程度，密实度的大小与其强度、耐水性和导热性等很多性质有关。 材料的密度、表观密度与堆积密度 材料的密度、表观密度与堆积密度 1、密度：密度是材料在绝对密实状态下，单位体积的质量。——密度自身体积 （不含孔隙）磨成细粉消除内部孔隙，材料的排水体积 V 计算式ρ= m/v 式中ρ--- 材料的密度，g/㎝3 。 m --- 材料在干燥状态下的质量，g 。 v --- 材料在绝对密实状态下的体积，㎝3。

霍尔传感器用法

一、霍尔电流电压传感器、变送器的基本原理与使用方法 1．霍尔器件 霍尔器件是一种采用半导体材料制成的磁电转换器件。如果在输入端通入控 制电流I C ，当有一磁场B穿过该器件感磁面，则在输出端出现霍尔电势V H 。 如图1－1所示。 霍尔电势V H 的大小与控制电流I C 和磁通密度B的乘积成正比，即：V H ＝K H I C Bsin Θ 霍尔电流传感器是按照安培定律原理做成，即在载流导体周围产生一正比于该电流的磁场，而霍尔器件则用来测量这一磁场。因此，使电流的非接触测量成为可能。 通过测量霍尔电势的大小间接测量载流导体电流的大小。因此，电流传感器经过了电－磁－电的绝缘隔离转换。 2．霍尔直流检测原理 如图1－2所示。由于磁路与霍尔器件的输出具有良好的线性关系，因此霍尔 器件输出的电压讯号U 0可以间接反映出被测电流I 1 的大小，即：I 1 ∝B 1 ∝U 我们把U 0定标为当被测电流I 1 为额定值时，U 等于50mV或100mV。这就制成 霍尔直接检测（无放大）电流传感器。

3．霍尔磁补偿原理 原边主回路有一被测电流I1，将产生磁通Φ1，被副边补偿线圈通过的电流I2所产生的磁通Φ2进行补偿后保持磁平衡状态，霍尔器件则始终处于检测零磁通的作用。所以称为霍尔磁补偿电流传感器。这种先进的原理模式优于直检原理模式，突出的优点是响应时间快和测量精度高，特别适用于弱小电流的检测。霍尔磁补偿原理如图1－3所示。 从图1－3知道：Φ 1＝Φ 2 I 1N 1 ＝I 2 N 2 I 2＝N I /N 2 ·I 1 当补偿电流I 2流过测量电阻R M 时，在R M 两端转换成电压。做为传感器测量电 压U 0即：U ＝I 2 R M 按照霍尔磁补偿原理制成了额定输入从0.01A～500A系列规格的电流传感器。 由于磁补偿式电流传感器必须在磁环上绕成千上万匝的补偿线圈，因而成本增加；其次，工作电流消耗也相应增加；但它却具有直检式不可比拟的较高精度和快速响应等优点。 4．磁补偿式电压传感器 为了测量mA级的小电流，根据Φ 1＝I 1 N 1 ，增加N 1 的匝数，同样可以获得高磁 通Φ 1 。采用这种方法制成的小电流传感器不但可以测mA级电流，而且可以测电压。 与电流传感器所不同的是在测量电压时，电压传感器的原边多匝绕组通过串 联一个限流电阻R 1，然后并联连接在被测电压U 1 上，得到与被测电压U 1 成比 例的电流I 1 ，如图1－4所示。

霍尔电流传感器及其应用

霍尔电流传感器及其应用 在现代社会中,信息化的需求越来越庞大，传感器在信息采集中发挥了重要作用。他们可以把各种物理信息，按照一定的规则，为可测量的电信号。我们所测量的电信号，以及相关物理信息的关系的变化的基础上，我们可以得到所测量的物理的变化或大小。 根据该传感器的工作原理，我们可以划分成多种类型的传感器，如光电传感器，电荷传感器，电位型传感器，半导体传感器，电传感器，磁传感器，谐振式传感器，电动化学式传感器等等。 霍尔传感器是利用霍尔元件的霍尔效应原理，（可以音乐会的物理信息），如电流，磁场，位移，压力等，为电动势输出。它属于电位型传感器。当前，这种传感器主要是霍尔集成电路，核心单元是基于霍尔效应。这是由通过集成电路技术。因此，它不仅仅是一种集成电路，而是一种磁传感器。 本文根据实际应用，主要是霍尔电流传感器。 1 霍尔效应 在金属或半导体晶片放置在磁场中，并且如果有一个通过它的电流，会产生电动势，（在垂直方向上的电场和磁场，调用此种物理现象霍尔效应。） 在磁场中产生的洛伦兹力的作用下，通电的半导体芯片的载体，分别偏移积累到芯片的两侧，从而形成一个电场，称霍尔电场。霍尔电场产生的电场力，是相反的洛伦兹力，阻碍了继续堆积，直到（大厅）电场力和洛伦兹力。此时，芯片的两侧，将设置一个稳定的电压，这是霍尔电压。 2 霍尔电流传感器 随着城市人口和城市建设规模的扩大，以及各种电气设备的增加，功耗也越来越大。城市的供电设备经常超载，而电源环境越来越差，“测试”的权利越来越严重。因此电源问题越来越多的显现出来。现在，小功率电源设备已经越来越多的与新技术相结合。例如，开关电源，硬切换，软切换，参数稳压器，线性反馈稳压器，磁放大器技术，数控压力调节，PWM,,SPWM，电磁兼容等实际需求直接推动电源技术的发展和进步。为了检验并显示当前自动，自动保护功能和更先进的智能控制，过电流，过电压的危害。如发生时，电源技术与传感检测，传感采样，传感保护已成为一种趋势。传感器检测电流或电压，所谓的霍尔电流传感器应运而生，(并迅速成为最喜爱的设计师在我国的电源). 2.1 霍尔电流传感器的性能特性 霍尔电流传感器具有优越的性能，并且它是一种先进的电检测元件，它可以隔离主回路和电子控制电路。它有变压器和分流器的所有优点，并且在同一时间，克服了他们的缺点（变压器可以只施加的电源频率的测量，50赫兹，分流器是无法做隔离测量），使用同一个霍尔电流传感器模块检测元素，不仅可以测量AC,也可以检测直流，甚至可以检测瞬时峰值。它具有以下性能特点。 (1)测量任意波形的电流，如DC,AC乃至瞬态峰值参数测量的； (2)精度高。在工作区中的一般霍尔电流传感器模块的精度高于1%，并且是适用于任何波形测量精度； (3)线性度优于0.5%； (4)良好的动态性能。一般的电流传感器模块的动态响应时间小于7us，跟踪速度di|dt 是上述50A|us； (5)工作频段宽。它可以工作在频率范围从0到20KHZ非常好; (6)过载能力强。测量范围宽（0-10000A); (7)高可靠性。平均无故障工作是超过5*10000小时； (8)体积小，重量轻，易于安装系统，不会带来任何损失。

表观密度与堆积密度

密度、表观密度与堆积密度 (1) 密度 密度是指材料在绝对密实状态下单位体积的质量。按下式计算： 式中ρ——密度，g/cm3； m——材料的质量，g； V——材料在绝对密实状态下的体积，cm3。 绝对密实状态下的体积是指不包括孔隙在内的体积。所以材料的密度大小取决于材料的组成与材料的微观结构，当材料的组成与结构一定时，材料的密度为常数。除了钢材、玻璃等少数材料外，绝大多数材料都有一些孔隙。在测定有孔隙材料的密度时，应把材料磨成细粉，干燥后，用李氏瓶测定其实体积。材料磨得越细，测得的密度数值就越精确。砖、石材等块状材料的密度即用此法测得。 (2) 表观密度 表观密度是指材料在自然状态下单位体积的质量，按下式计算： 式中ρo——表观密度，g/cm3或kg/cm3； m——材料的质量，g或kg； V o——材料在自然状态下的体积，或称表观体积，cm3或m3。 材料的表观体积是指材料及所含内部孔隙的总体积，材料在自然状态下的质量与其含水状态关系密切，且与材料孔隙的具体构造特征

有关。故测定表观密度时，必须注明其含水情况，一般是指材料在气干状态（长期在空气中干燥）下的表观密度。在烘干状态下的表观密度，称为干表观密度。不含开口孔隙的表观密度称为视密度，以排水法测定其体积。 (3) 堆积密度 堆积密度是指粉状或粒状材料在堆积状态下单位体积的质量，按下式计算： 式中——堆积密度，kg/m3； m——材料的质量，kg； ——材料的堆积体积，m3。 测定散粒材料的堆积密度时，材料的质量是指填充在一定容器内的任意含水状态下的质量。但须注明含水率，其堆积体积是指所用容器的容积而言。因此，材料的堆积体积包含了颗粒内部的孔隙及颗粒之间的空隙。材料的堆积密度与材料的表观密度、堆积的紧密程度有关。在捣实状态下测定的堆积密度称为紧密堆积密度。 表观密度 英文名称: Apparent density

霍尔电流传感器工作原理

霍尔电流传感器工作原理 1、直放式（开环）电流传感器（CS系列） 当原边电流I P流过一根长导线时，在导线周围将产生一磁场，这一磁场的大小与流过导线的电流成正比，产生的磁场聚集在磁环内，通过磁环气隙中霍尔元件进行测量并放大输出，其输出电压V S精确的反映原边电流I P。一般的额定输出标定为4V。 2、磁平衡式（闭环）电流传感器（CSM系列） 磁平衡式电流传感器也称补偿式传感器，即原边电流Ip在聚磁环处所产生的磁场通过一个次级线圈电流所产生的磁场进行补偿，其补偿电流Is精确的反映原边电流Ip，从而使霍尔器件处于检测零磁通的工作状态。 具体工作过程为：当主回路有一电流通过时，在导线上产生的磁场被磁环聚集并感应到霍尔器件上，所产生的信号输出用于驱动功率管并使其导通，从而获得一个补偿电流Is。这一电流再通过多匝绕组产生磁场，该磁场与被测电流产生的磁场正好相反，因而补偿了原来的磁场，使霍尔器件的输出逐渐减小。当与Ip与匝数相乘所产生的磁场相等时，Is不再增加，这时的霍尔器件起到指示零磁通的作用，此时可以通过Is来测试Ip。当Ip变化时，平衡受到破坏，霍尔器件有信号输出，即重复上述过程重新达到平衡。被测电流的任何变化都会破坏这一平衡。一旦磁场失去平衡，霍尔器件就有信号输出。经功率放大后，立即就有相应的电流流过次级绕组以对失衡的磁场进行补偿。从磁场失衡到再次平衡，所需的时间理论上不到1μs，这是一个动态平衡的过程。因此，从宏观上看，次级的补偿电流安匝数在任何时间都与初级被测电流的安匝数相等。 3、霍尔电压（闭环）传感器（VSM系列）

霍尔电压传感器的工作原理与闭环式电流传感器相似，也是以磁平衡方式工作的。原边电压VP通过限流电阻Ri产生电流，流过原边线圈产生磁场，聚集在磁环内，通过磁环气隙中霍尔元件输出信号控制的补偿电流IS流过副边线圈产生的磁场进行补偿，其补偿电流IS精确的反映原边电压VP。 4、交流电流传感器（A-CS系列） 交流电流传感器主要测量交流信号灯电流。是将霍尔感应出的交流信号经过AC-DC及其他转换，变为0～4V、0～20mA（或4～20mA）的标准直流信号输出供各种系统使用。

细集料表观密度堆积密度及空隙率

细集料表观密度、堆积密度及空隙率 一、表观密度 1.仪器设备： 本试验用仪器设备如下： a）鼓风干燥箱：能使温度控制在（105±5）℃； b）天平：称量1000g，感量0.1g； c）容量瓶：500ml； d）干燥器、搪瓷盘、滴管、毛刷、温度计等。 2.实验步骤： 1）按规定取样方法取样，并将试样缩分至约660g，放在干燥箱中于（105±5）℃ 下烘干至恒重，待冷却至室温后，分为大致相等的两份备用。 2）称取试样300g，精确至0.1g。将试样装入容量瓶，注入冷开水至接近500ml 的刻度线处，用手旋转摇动容量瓶，使砂样充分摇动，排除气泡，塞紧瓶盖，静 置24h。然后用滴管小心加水至容量瓶500ml刻度处，塞紧瓶盖，擦干瓶外水分，称出其质量，精确至1g。 3）倒出瓶内水和试样，洗净容量瓶，再向容量瓶内注水（应与步骤“2）”水温 相差不超过2℃，并在15℃～25℃范围内）至500ml刻度处，塞紧瓶塞，擦干瓶 外水分，称出其质量，精确至1g。 注：在砂的表观密度试验过程中应测量并控制水的温度，试验的各项称量可在15℃～25℃的温度范围内进行。从试样加水静置的最后2h起直至 试验结束，其温度相差不应超过2℃。 3.结果计算与评定： 1）砂的表观密度按下式计算，精确至10kg/m3: 2）表观密度取两次试验结果的算术平均值，精确至10kg/m3；如两次试验结果之 差大于20kg/m3，应重新试验。 3）采用修约值比较法进行评定。

二、堆积密度与空隙率 1.仪器设备： 本试验用仪器设备如下： a）鼓风干燥箱：能使温度控制在（105±5）℃； b）天平：称量1000g，感量0.1g； c）容量筒：圆柱形金属筒，内经108mm，净高109mm，壁厚2mm，筒底厚约5mm，容积为1L； d）方孔筛：孔径为4.75mm的筛一只； e）垫棒：直径10mm，长500mm的圆钢； f）直尺、漏斗或料勺、搪瓷盘、毛刷等。 2.试验步骤： 1）按照规定取样方法取样，用搪瓷盘装取试样约3L，放在干燥箱中于（105±5）℃下烘干至恒重，待冷却至室温后，筛除大于4.75mm的颗粒，分为大致相等的两份备用。 2）松散堆积密度：取试样一份，用漏斗或料勺将试样从容量筒中心上方50mm 处徐徐倒入，让试样以自由落体落下，当容量筒上部试样呈椎体，且容量筒四周溢满时，即停止加料。然后用直尺沿筒口中心线向两边刮平（试验过程应防止触动容量筒），称出试样和容量筒总质量，精确至1g。 3）紧密堆积密度：取式样一份分为二次装入容量筒。装完第一层后（约计稍高于1/2），在筒底垫放一根直径为10mm的圆钢，将筒按住，左右交替击地面各25下。然后装入第二层，第二层装满后用同样方法颠实（但筒底所垫钢筋的方向与第一层时的方向垂直）后，再加试样直至超过筒口，然后用直尺沿筒口中心线向两边刮平，称出试样和容量筒总质量，精确至1g。 3.结果计算与评定： 1）松散或紧密堆积密度按下式计算，精确至10kg/m3: 2）空隙率按下式计算，精确至1%： 3）堆积密度取两次试验结果的算术平均值，精确至10kg/m3。空隙率取两次试验结果的算术平均值，精确至1%。

霍尔电流传感器的应用

霍尔电流传感器的应用 霍尔电流传感器广泛应用在变频调速装置、逆变装置、UPS电源、通信电源、电焊机、电力机车、变电站、数控机床、电解电镀、微机监测、电网监测等需要隔离检测电流的设施中以及新兴的太阳能、风能和地铁轨道信号、汽车电子等领域。 1、继电保护与测量： 在工业应用中，来自高压三相输电线路电流互感器的二次电流，如分别经三只霍尔电流传感器，按比例转换成毫伏电压输出，然后再经运算放大器放大及有源滤波，得到符合要求的电压信号，可送微机进行测量或处理。在这里使用霍尔电流传感器可以很方便地实现了无畸变、无延时的信号转换。 2、在直流自动控制调速系统中的应用： 在直流自动控制调速系统中，用霍尔电流电压传感器可以直接代替电流互感器，不仅动态响应好，还可实现对转子电流的最佳控制以及对晶闸管进行过载保护。 3、在逆变器中的应用： 在逆变器中，用霍尔电流传感器可进行接地故障检测、直接测和交流测的模拟量传感，以保证逆变器能安全工作。 4、在不间断电源中的应用： 在该应用中，用霍尔电流传感器进行控制，保证逆变电源正常工作。使用①霍尔电流传感器发出信号并进行反馈，以控制晶闸管的触发角，②霍尔电流传感器发出的信号控制逆变器，③

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简单易懂的霍尔电流传感器使用原理及相关霍尔型

简单易懂的霍尔电流传感器使用原理及相关霍 尔型 集团公司文件内部编码：（TTT-UUTT-MMYB-URTTY-ITTLTY-

1、开环（直放式）霍尔电流传感器 当原边电流I P 流过一根长导线时，在导线周围将产生一磁场，这一磁场的大小与流过导线的电流成正比，产生的磁场聚集在磁环内，通过磁环气隙中霍尔元件（如HG-302C） 进行测量并放大输出，其输出电压V S 精确的反映原边电流I P 。一般的额定输出标定为 4V。开环霍尔电流传感器的优点是结构简单，可靠性好，过载能力强，体积较小，开环式霍尔电流传感器一般线性度角差，且原边信号在上升和下降过程中副边输出会有不同。开环式霍尔电流传感器精度通常劣于1%。?一般开环电流传感器采用的霍尔是HG-106A,HG-106C,HG-166A,HG-302A,HG-302C,HG-362A,SS495A,SS495A1。 2、闭环（磁平衡式）霍尔电流传感器 磁平衡式电流传感器也称补偿式传感器，即原边电流Ip在聚磁环处所产生的磁场通过一个次级线圈电流所产生的磁场进行补偿，其补偿电流Is精确的反映原边电流Ip，从而使霍尔器件（如HW-300B,HW-302B）处于检测零磁通的工作状态。 当主回路有一电流通过时，在导线上产生的磁场被磁环聚集并感应到霍尔器件上，所产生的信号输出用于驱动功率管并使其导通，从而获得一个补偿电流Is。这一电流再通过多匝绕组产生磁场，该磁场与被测电流产生的磁场正好相反，因而补偿了原来的磁场，使霍尔器件的输出逐渐减小。当与Ip与匝数相乘所产生的磁场相等时，Is不再增加，这时的霍尔器件起到指示零磁通的作用，此时可以通过Is来测试Ip。当Ip变化时，平衡受到破坏，霍尔器件有信号输出，即重复上述过程重新达到平衡。被测电流的任何变化都会破坏这一平衡。一旦磁场失去平衡，霍尔器件（HW-300B,HW-302B）就有信号输出。经功率放大后，立即就有相应的电流流过次级绕组以对失衡的磁场进行补偿。从磁场失衡到再次平衡，所需的时间理论上不到1μs，是一个动态平衡的过程。因此，宏观上看，次级的补

简单易懂的霍尔电流传感器使用原理及相关霍尔型

简单易懂的霍尔电流传感器使用原理及相关霍尔型 This model paper was revised by the Standardization Office on December 10, 2020

简单易懂的霍尔电流传感器使用原理及相关霍尔型号推荐 1、开环（直放式）霍尔电流传感器 当原边电流I P 流过一根长导线时，在导线周围将产生一磁场，这一磁场的大小与流过导线的电流成正比，产生的磁场聚集在磁环内，通过磁环气隙中霍尔元件（如HG-302C） 进行测量并放大输出，其输出电压V S 精确的反映原边电流I P 。一般的额定输出标定为 4V。开环霍尔电流传感器的优点是结构简单，可靠性好，过载能力强，体积较小，开环式霍尔电流传感器一般线性度角差，且原边信号在上升和下降过程中副边输出会有不同。开环式霍尔电流传感器精度通常劣于1%。一般开环电流传感器采用的霍尔是HG-106A,HG-106C,HG-166A,HG-302A,HG-302C,HG-362A,SS495A,SS495A1。 2、闭环（磁平衡式）霍尔电流传感器 磁平衡式电流传感器也称补偿式传感器，即原边电流Ip在聚磁环处所产生的磁场通过一个次级线圈电流所产生的磁场进行补偿，其补偿电流Is精确的反映原边电流Ip，从而使霍尔器件（如HW-300B, HW-302B）处于检测零磁通的工作状态。 当主回路有一电流通过时，在导线上产生的磁场被磁环聚集并感应到霍尔器件上，所产生的信号输出用于驱动功率管并使其导通，从而获得一个补偿电流Is。这一电流再通过多匝绕组产生磁场，该磁场与被测电流产生的磁场正好相反，因而补偿了原来的磁场，使霍尔器件的输出逐渐减小。当与 Ip与匝数相乘所产生的磁场相等时，Is不再增加，这时的霍尔器件起到指示零磁通的作用，此时可以通过Is来测试Ip。当Ip变化时，平衡受到破坏，霍尔器件有信号输出，即重复上述过程重新达到平衡。被测电流的任何变化都会破坏这一平衡。一旦磁场失去平衡，霍尔器件（HW-300B,HW-302B）就有信号输出。经功率放大后，立即就有相应的电流流过次级绕组以对失衡的磁场进行补偿。从磁场失衡到再次平衡，所需的时间理论上不到1μs，是一个动态平衡的过程。因此，宏观上看，次级的补偿电流安匝数在任何时间都与初级被测电流的安匝数相等。一般来说闭环式电流传感器比开环电流传感器的精度更高，闭环霍尔电流传感器等特点是精度高，响应快，频带宽。闭环式霍尔电流传感器由于工作在零磁通状态，磁芯的非线性及磁滞效应不对输出造成影响，可以获得较好的线性度和较高的精度。闭环式霍尔电流传感器精度一般可达%。 闭环霍尔电流传感器一般采用的霍尔是HW-300B,HW-302B,HW-322B。

浅析霍尔电流传感器的应用

浅析霍尔电流传感器的应用 2006-6-26 15:35:00转自《仪器仪表交易网》供稿 一、前言伴随着城市人口和建设规模的扩大，各种用电设备的增多，用电量越来越大，城市的供电设备经常超负荷运转，用电环境变得越来越恶劣，对电源的“考验”越来越严重。据统计，每天，用电设备都要遭受120次左右各种的电源问题的侵扰，电子设备故障的60%来自电源.因此，电源问题的重要性日益凸显出来。原先作为配角，资金投入较少的电源越来越受到厂商和研究人员的重视，电源技术遂发展成为一门崭新的技术。 而今，小小的电源设备已经融合了越来越多的新技术。例如开关电源、硬开关、软开关、参数稳压、线性反馈稳压、磁放大器技术、数控调压、PWM、SPWM、电磁兼容等等。实际需求直接推动电源技术不断发展和进步，为了自动检测和显示电流，并在过流、过压等危害情况发生时具有自动保护功能和更高级的智能控制，具有传感检测、传感采样、传感保护的电源技术渐成趋势，检测电流或电压的传感器便应运而生并在我国开始受到广大电源设计者的青睐，本文主要介绍南京中旭电子科技有限公司的电流传感器。 二、电流传感器的工作原理 南京中旭电子科技有限公司的电流传感器可以测量各种类型的电流，从直流电到几十千赫兹的交流电，其所依据的工作原理主要是霍尔效应原理。（本文下面多以以零磁通闭环产品原理为例） 当原边导线经过电流传感器时，原边电流IP会产生磁力线，原边磁力线集中在磁芯气隙周围，内置在磁芯气隙中的霍尔电片可产生和原边磁力线成正比的，大小仅为几毫伏的感应电压，通过后续电子电路可把这个微小的信号转变成副边电流IS，并存在以下关系式：IS* NS= IP*NP 其中，IS—副边电流； IP—原边电流； NP—原边线圈匝数； NS—副边线圈匝数； NP/NS—匝数比，一般取NP=1。 电流传感器的输出信号是副边电流IS，它与输入信号（原边电流IP）成正比，IS一般很小，只有10~40 0mA。如果输出电流经过测量电阻RM，则可以得到一个与原边电流成正比的大小为几伏的电压输出信号。 2、传感器供电电压VA VA指电流传感器的供电电压，它必须在传感器所规定的范围内。超过此范围，传感器不能正常工作或可靠性降低，另外，传感器的供电电压VA又分为正极供电电压VA+和负极供电电压VA-。要注意单相供电的传感器，其供电电压VAmin是双相供电电压VAmin的2倍，所以其测量范围要相供高于双电的传感器。 3、测量范围Ipmax 测量范围指电流传感器可测量的最大电流值，测量范围一般高于标准额定值IPN。 三、电流传感器主要特性参数 1、标准额定值IPN和额定输出电流ISNIPN指电流传感器所能测试的标准额定值，用有效值表示（A.r. m.s），IPN的大小与传感器产品的型号有关。ISN指电流传感器额定输出电流，一般为10~400mA，当然根据某些型号具体可能会有所不同。 2、偏移电流ISO 偏移电流也叫残余电流或剩余电流，它主要是由霍尔元件或电子电路中运算放大器工作状态不稳造成的。电流传感器在生产时，在25℃，IP=0时的情况下，偏移电流已调至最小，但传感器在离开生产线时，都会产生一定大小的偏移电流。产品技术文档中提到的精度已考虑了偏移电流增加的影响。

霍尔电流传感器的应用

霍尔电流传感器的应用 霍尔电流传感器的应用 霍尔电流传感器的应用场合1、在逆变器中的应用：在逆变器中，用霍尔电流传感器可进行接地故障检测、直接侧和交流侧的模拟量传感，以保证逆变器能安全工作。2、在直流自动控制调速系统中的应用：在直流自动控制调速系统中，用霍尔电流电压传感器可以直接代替电流互感器，不仅动态响应好，还可实现对转子电流的最佳控制以及对晶闸管进行过载保护。3、继电保护与 测量：在工业应用中，来自高压三相输电线路电流互感器的二次电流，如分别经三只霍尔电流传感器，按比例转换成毫伏电压输出，然后再经运算放大器放大及有源滤波，得到符合要求的电压信号，可送微机进行测量或处理。在这里使用霍尔电流传感器可以很方便地实现了无畸变、无延时的信号转换。 4、在不间断电源中的应用：在该应用中，用霍尔电流传感器进行控制，保证逆变电源正常工作。使用霍尔电流传感器1 发出信号并进行反馈，以控制晶闸管的触发角，霍尔电流传感器2 发出的信号控制逆变器，霍尔电流传感器3 控制浮充电源。由于其响应速度快，霍尔电流传感器特别适用于计算机中的不间断电源。 5、在电子点焊机中的应用：在电子点焊机电源中，霍尔电流传感器起测量和控制作用。它的快速响应能再现电流、电压波形，将它们反馈到可控整流器A、B，可控制其输出。用斩波器给直流迭加上一个交流，可更精 确地控制电流。用霍尔电流传感器进行电流检测，既可测量电流的真正瞬时值，又不致引入损耗。 6、用于电车斩波器的控制：电车中的调速是由调整电压实现的。而将霍尔电流传感器和其它元件配合使用，并将传感器的所有信号输入控制系统，可确保电车正常工作。 7、在交流变频调速电机中的应用：用变频器来对交流电