Demand curve of a firm is perfectly elastic under : (Choose the correct alternative)

(a) Perfect competition

(b) Monopoly

(c) Monopolistic competition

(d) Oligopoly

When does ‘change in demand’ take place?

The differentiated product is a characteristic of (Choose the correct alternative) :

(a) Monopolistic competition only

(b) Oligopoly only

(c) Both monopolistic competition and oligopoly

(d) Monopoly

A consumer consumes only two goods X and Y. Marginal utilities of X and Y are 3 and 4 respectively. Prices of X and Y are ` 4 per unit each. Is consumer in equilibrium? What will be the further reaction of the consumer ? Give reasons.

What will be the effect of a 10 per cent rise in the price of a good on its demand if the price elasticity of demand is (a) Zero, (b) 21, (c) 22?