Movement along the Demand Curve: Extension and Contraction Video Lecture | Microeconomics- Interaction between individual buyer-seller

in this lecture we will discuss
movements along a demand curve
now you know that the quantity demanded
of a good depends not only on its price
but also on many other factors like
income of a consumer tastes and
preferences etc however when we draw a
demand curve we take only two axis
vertical axis and horizontal axis and
this is because we can only draw up to
two dimensions on a plane so we
represent price on the vertical axis and
quantity demanded on the horizontal axis
so there is no way to represent other
factors that affect the quantity
demanded on this graph so while drawing
the demand curve we assume that all the
other factors are constant movement
along the demand curve happens when
there is a change in a relevant variable
that we have taken on these two axis in
the demand curve shown here when price
of an ice cream cup falls from $4 to $2
the quantity demanded increases from 2
units to 6 units as we have taken price
of an ice cream cup on the vertical axis
when the price decreases the consumer
moves down along the demand curve from
point A to point B this increase in
quantity demanded of good due to
decrease in price of that good is called
extension of demand
similarly when quantity demanded of the
good Falls due to increase in price of
that good it is called contraction of
demand graphically it means a movement
along the demand curve from Point C to
point B so this is all about the
movements along a demand curve