Class 12 Micro Economics - Chapter The Theory of the Firm under Perfect Competition NCERT Solutions | What conditions must hold if a profit-ma

The market price of a good changes from Rs 5 to Rs 20. As a result, the quantity supplied by a firm increases by 15 units. The price elasticity of the firm’s supply curve is 0.5. Find the initial and final output levels of the firm.

A firm earns a revenue of Rs 50 when the market price of a good is Rs 10. The market price increases to Rs 15 and the firm now earns a revenue of Rs 150. What is the price elasticity of the firm’s supply curve?

What is the supply curve of a firm in the long run?

How does the imposition of a unit tax affect the supply curve of a firm?

What is the relation between market price and average revenue of a price-taking firm?

What is the relation between market price and marginal revenue of a price-taking firm?

How does an increase in the number of firms in a market affect the market supply curve?

How does an increase in the price of an input affect the supply curve of a firm?

Compute the total revenue, marginal revenue and average revenue schedules in the following table. Market price of each unit of the good is Rs 10.

How does technological progress affect the supply curve of a firm?

Explain the concept of a production function

What would be the shape of the demand curve so that the total revenue curve is?

(a) A positively sloped straight line passing through the origin?

(b) A horizontal line?

Explain market equilibrium.

Discuss the central problems of an economy.

What do you mean by the budget set of a consumer?

What is the total product of input?

From the schedule provided below calculate the total revenue, demand curve and the price elasticity of demand:

When do we say that there is an excess demand for a commodity in the market?

What do you mean by the production possibilities of an economy?

What is budget line?

How does the budget line change if the price of good 2 decreases by a rupee
but the price of good 1 and the consumer’s income remain unchanged?

What do the long-run marginal cost and the average cost curves look like? 

Suppose the demand and supply curves of salt are given by:

(a) Find the equilibrium price and quantity.

(b) Now, suppose that the price of an input that used to produce salt has increased so, that the new supply curve is qs = 400 + 3p

How does the equilibrium price and quantity change? Does the change conform to your expectation?

(a) Suppose the government has imposed at ax of Rs 3 per unit of sale on salt. How does it affect the equilibrium rice quantity? 

A consumer wants to consume two goods. The prices of the two goods are Rs 4
and Rs 5 respectively. The consumer’s income is Rs 20.
(i) Write down the equation of the budget line.
(ii) How much of good 1 can the consumer consume if she spends her entire
income on that good?
(iii) How much of good 2 can she consume if she spends her entire income on
that good?
(iv) What is the slope of the budget line?
Questions 5, 6 and 7 are related to question 4.

Suppose there are two consumers in the market for a good and their demand functions are as follows:

d1(p) = 20 – p for any price less than or equal to 20, and d1(p) = 0 at any price greater than 20.

d2(p) = 30 – 2p for any price less than or equal to 15 and d1(p) = 0 at any price greater than 15.

Find out the market demand function.

How will a change in the price of coffee affect the equilibrium price of tea? Explain the effect on equilibrium quantity also through a diagram. 

Suppose the price elasticity of demand for a good is – 0.2. How will the expenditure on the good be affected if there is a 10 % increase in the price of the good?

Explain why the budget line is downward sloping.

What do you mean by ‘monotonic preferences’?

Suppose there was a 4 % decrease in the price of a good, and as a result, the expenditure on the good increased by 2 %. What can you say about the elasticity of demand?