Class 12 Micro Economics - Chapter Theory of Consumer Behaviour NCERT Solutions | What is budget line?

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 your friend is indifferent to the bundles (5, 6) and (6, 6). Are the preferences of your friend monotonic?

Suppose there are 20 consumers for a good and they have identical demand functions: 

d(p)=10–3pd(p)=10–3p for any price less than or equal to 103103 and d1(p)=0d1(p)=0 at any price greater than 103.

Explain why the budget line is downward sloping.

What do you mean by an ‘inferior good’? Give some examples

Consider the demand curve D (p) = 10 – 3p. What is the elasticity at price 53?

Suppose a consumer’s preferences are monotonic. What can you say about her preference ranking over the bundles (10, 10), (10, 9) and (9, 9)?

Suppose a consumer wants to consume two goods which are available only in
integer units. The two goods are equally priced at Rs 10 and the consumer’s
income is Rs 40.
(i) Write down all the bundles that are available to the consumer.
(ii) Among the bundles that are available to the consumer, identify those which cost her exactly Rs 40.

Explain price elasticity of demand.

What do you mean by substitutes? Give examples of two goods which are substitutes of each other.

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 are the characteristics of a perfectly competitive market?

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?

How are the total revenue of a firm, market price, and the quantity sold by the firm related to each other?

What is the reason for the long run equilibrium of a firm in monopolistic competition to be associated with zero profit?

If the price of a substitute Y of good X increases, what impact does it have on the equilibrium price and quantity of good X?

When does a production function satisfy decreasing returns to scale? 

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. 

What is the marginal product of an input? 

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

When does a production function satisfy constant returns to scale?

Compare the effect of shift in the demand curve on the equilibrium when the number of firms in the market is fixed with the situation when entry-exit is permitted.

Suppose the demand and supply curve of commodity XX in a perfectly competitive market are given by:

qD =700 - p

qs = 500 + 3p for p ≥ 15

= 0 or 0 ≤ p <15

Assume that the market consists of identical firms. Identify the reason behind the market supply of commodity X being zero at any price less than Rs 15. What will be the equilibrium price for this commodity? At equilibrium, what quantity of X will be produced?

What is the ‘price line’?