A) \[\frac{mg}{il}\sin \theta \]
B) \[\frac{mg}{il}\tan \theta \]
C) \[\frac{mg\cos \theta }{il}\]
D) \[\frac{mg}{il\,\sin \,\theta }\]
Correct Answer: B
Solution :
Magnetic force \[{{\overrightarrow{F}}_{m}}=ilB\] acts in the direction as shown in given figure. Rod will move downwards with constant velocity, if net force on it is zero. or \[{{F}_{m}}\cos \theta =mg\sin \theta \] or \[ilB\cos \theta =mg\sin \theta \] \[\therefore \] \[B=\left( \frac{mg}{il} \right)\tan \theta \]You need to login to perform this action.
You will be redirected in
3 sec