Q1. The short-run supply curve for a price taker firm is the portion of the marginal cost (MC) curve:

A)     below the average variable cost (AVC) curve.

B)     above the average variable cost (AVC) curve.

C)     above the average total cost (ATC) curve.

Q2. The short-run supply curve for a firm in a perfectly competitive market is equal to the firm's:

A)   AVC curve.

B)   ATC curve.

C)   MC curve.

Q3. Under perfect competition, the short-run market supply curve is most accurately described by which of the following statements? The market short-run supply curve is the:

A)   sum of the quantities at each price along the average total cost curve for all firms in a given industry.

B)   sum of the quantities at each price along the marginal cost curves for all firms in a given industry.

Q4. The short-run supply curve to a firm operating under perfect competition is most accurately described as the segment of the:

A)   marginal cost (MC) curve above the average variable cost (AVC) curve.

B)   marginal cost (MC) curve below the average total cost (ATC) curve.

C)   average total cost (ATC) curve above the average variable cost (AVC) curve.

Q5. In a perfectly competitive industry, the short-run supply curve for the market is the:

A)   marginal cost curve above the average total cost curve.

B)   marginal cost curve above the average variable cost curve.

C)   sum of the individual supply curves for all firms in the industry.

[此贴子已经被作者于2009-1-6 13:49:56编辑过]

答案和详解如下：

Q1. The short-run supply curve for a price taker firm is the portion of the marginal cost (MC) curve:

A)     below the average variable cost (AVC) curve.

B)     above the average variable cost (AVC) curve.

C)     above the average total cost (ATC) curve.

Correct answer is B)

The short-run supply curve for a firm is its MC curve above the AVC curve. Price takers will produce where price (P) equals MC. At prices below the AVC curve the firm will not be able to remain in operation. Above the ATC curve the firm is making economic profits and will continue to expand production along the MC curve.

Q2. The short-run supply curve for a firm in a perfectly competitive market is equal to the firm's:

A)   AVC curve.

B)   ATC curve.

C)   MC curve.

Correct answer is C)

The short-run supply curve for a firm in a perfectly competitive market is equal to the firm's MC curve. A price taker will maximize profits when it produces the output level where P = MC. As price rises, its point of intersection with the MC curve indicates optimal production.

Q3. Under perfect competition, the short-run market supply curve is most accurately described by which of the following statements? The market short-run supply curve is the:

A)   sum of the quantities at each price along the average total cost curve for all firms in a given industry.

B)   sum of the quantities at each price along the marginal cost curves for all firms in a given industry.

C)   average of the quantities at each price along the marginal cost curve for all firms in a given industry.

Correct answer is B)         

The short-run market supply curve is the horizontal sum of the marginal cost curves for all firms in a given industry. It is the sum of all quantities from all firms at each price along each firm’s marginal cost curve.

Q4. The short-run supply curve to a firm operating under perfect competition is most accurately described as the segment of the:

A)   marginal cost (MC) curve above the average variable cost (AVC) curve.

B)   marginal cost (MC) curve below the average total cost (ATC) curve.

C)   average total cost (ATC) curve above the average variable cost (AVC) curve.

Correct answer is A)

The short-run supply curve for a firm under perfect competition is the segment of its MC curve above the AVC curve.

Q5. In a perfectly competitive industry, the short-run supply curve for the market is the:

A)   marginal cost curve above the average total cost curve.

B)   marginal cost curve above the average variable cost curve.

C)   sum of the individual supply curves for all firms in the industry.

Correct answer is C)

The short-run supply curve for a firm is its marginal cost curve above the average variable cost curve. The short-run supply curve of the market is the sum of the supply curves for all firms in the industry.

O(∩_∩)O谢谢

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