Question

Distinguish between change in quantity demanded and change in demand

Answer 1

Change in qty demanded  :

1. When quantity of a commodity demanded changes due to change in  the price of the commodity , keeping other factors constant, it is called change in the quantity demanded.
2. It leads to a movement along the demand curve.  The movement can be either contraction or expansion.
3. It occurs due to an increase in the price or due to a decrease in price.

Change in demand  :

1. When demand of a commodity changes due to change in factors other than its price, it is called change in demand.
2. It leads to a shift in the demand curve. The shift can be either rightward or leftward.
3. It occurs due to change in price of supplementary goods or change in technology.                          

Answer 2

Explanation:

A change in demand means that the entire demand curve shifts either left or right. ... A change in quantity demanded refers to a movement along the demand curve, which is caused only by a chance in price. In this case, the demand curve doesn't move; rather, we move along the existing demand curve.