A square frame of side L is dipped in a liquid. On taking out, a membrane is formed. If the surface tension of the liquid is T, the force acting on the frame will be
2 TL
4 TL
8 TL
10 TL
As we learnt in
Coefficient of viscosity -
A is the area of contact for liquid layers
is velocity gradient; the change in velocity with distance.
n is coefficient of viscosity.
-
Option 1)
2 TL
Incorrect
Option 2)
4 TL
Incorrect
Option 3)
8 TL
Correct
Option 4)
10 TL
Incorrect
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As after dipping the square frame it forms 2 layers of liquid
1- Frontside,F=T*L
2-Backside,F=T*L
So net force acting on frame will be T*L+T*L=2T*L(1) will be the correct answer