Mark the correct alternative in the following:
A cylindrical tank of radius 10 m is being filled with wheat at the rate of 314 cubic metre per hour. Then the depth of the wheat is increasing at the rate of
The volume of a cylinder, of radius r and height h, is defined as
V(r,h)=πr2h
Given that r=10m, we get
V(h)=π×102×h=100πh – (1)
Given that  , we have to calculate
, we have to calculate 
Differentiating (1) with respect to t, we get

Substituting values and using π=3.14, we get

⇒ 