question_answer

There is an electric field \[E\] in X-direction. If the work done on moving a charge \[0.2\,C\] through a distance of \[2\,m\] along a line making an angle \[60{}^\circ \] with the X-axis is 4.0, what is the value of \[E\]                                             [CBSE PMT 1995]

A)                    \[\sqrt{3}\,N/C\]

B)                                                 \[4\,N/C\]

C)                                                               \[5\,N/C\]

D)                                                 None of these

Correct Answer: D

Solution :

                     \[W=qV=qE.d\] Þ 4 = 0.2 ´ E ´ (2 cos 60o)         = 0.2 E ´ (2 ´ 0.5) \ \[E=\frac{4}{0.2}=20\,N{{C}^{-1}}\]