UPSC Civil Service Exam Questions - Engineering

Q1:

If the stream function is ψ = 2 xy, then the velocity at a point (1, 2) is equal to

A 2

B 4

C
20

D 16

ANS:C -

20

U=-d£/dy=-2x=-2*1=-2. V=d£/dx=2y=2*2=4.

Velocity=√{u^2+V2}=√20.