question_answer

A force of \[40N\]acts on a point \[B\] at the end of an L-shaped object, as shown in the figure. The angle \[0\] that will produce maximum moment of the force about point \[A\] is given by:                        [JEE Online 15-04-2018]

A)   \[\tan \theta =\frac{1}{4}\]      

B)        \[\tan \theta =2\]

C)   \[\tan \theta =\frac{1}{2}\]      

D)        \[\tan \theta =4\]

Correct Answer: C

Solution :

[c] Moment of force about point A will be given as

For maximum,