Q.

A square Lamina OABC of length 10 cm is pivoted at 'O'. Forces act at Lamina as shown in figure. If Lamina remains stationary, then the magnitude of F is:          [2025]

1 20 N  
2 0 (zero)  
3 10 N  
4 102 N  

Ans.

(3)

Since the Lamina is equilibrium.

The net torque about O = 0

Fl+10l10l+10l=0  F=10 N