Q.

A force F=2i^+bj^+k^ is applied on a particle and it undergoes a displacement i^2j^k^. What will be the value of b, if work done on the particle is zero.          [2025]

1 0  
2 12  
3 13  
4 2  

Ans.

(2)

Given, W = 0

 F·S=0

(2i^+bj^+k^)·(i^2j^k^)=0

22b1=0  b=12