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]
(2)
Given, W = 0
∴ F→·S→=0
(2i^+bj^+k^)·(i^–2j^–k^)=0
2–2b–1=0 ⇒ b=12