question_answer

As shown in figure the tension in the horizontal cord is 30 N. The weight W  and tension in the string OA in Newton are                                                 [DPMT 1992]

A)                          30\[\sqrt{3},\]30

B)                                 30\[\sqrt{3},\]60

C)                 60\[\sqrt{3},\]30

D)                                 None of these

Correct Answer: B

Solution :

                                    From the figure \[T\,\sin {{30}^{o}}=30\]              ?(i)                                          \[T\cos {{30}^{o}}=W\]         ?(ii)                 By solving equation (i) and (ii) we get                 \[W=30\sqrt{3}N\] and \[T=60N\]