If there is a positive level of output at which a firm's profit is maximized in the long run, three conditions must hold at that output level are:

A. P is equal to LRMC

B. P is less than LRAC

C. LRMC is non - decreasing

D. P is greater than or equal to the minimum LRAC

Choose the correct answer from the options given below:

What would be the equilibrium number of firms in a market of identical firms, when market demand function $(Q_d)$, supply function of a single firm $(Q_s1)$ and equilibrium price (P) are given as

$Q_d = 180 - 2P$

$Q_{s1} = 15 + P$

$P = 15$

1. 5
2. 6
3. 8
4. 9

Which of the following is NOT a condition for profit maximization of a perfectly competitive firm in the short run?

What is the shape of Average Revenue (AR) curve under perfect competition?

Under perfect competition if firms earn supernormal profits. Arrange following statements to arrive at the implication of free entry and exit of firms

(A) Market price fall in such a manner that firms will be earning normal profits only and thus no more firms will have incentive to enter the market.

(B) Some new firms will enter the market

(C) At the prevailing market price, each firm is earning supernormal profit.

(D) Demand remains unchanged but the market supply curve shifts rightward

Arrange the following statements related to negative externalities in correct sequence

(A) There is an oil refinery which refines crude petroleum and sells it in the market

(B) Pollution harms well-being and also kills fish or other organisms

(C) Production the refinery may also be polluting the nearby river

(D) Such harmful effects that the refinery is inflicting on others, for which it will not bear any cost, are called externalities

Identify the incorrect option from the following related to a perfectly competitive market.