Question

If OP makes 4 revolutions in one second, the angular velocity in radians per second is
(a) π
(b) 2 π
(c) 4 π
(d) 8 π

Answer 1

(d) 8π

$$\begin{gathered} \mathrm{Angular}\mathrm{velocity}=\frac{\mathrm{Distance}}{\mathrm{Time}} \\ =\frac{4\mathrm{revolutions}}{1\mathrm{second}} \\ =\frac{4\times 2\mathrm{\pi }}{1}\left(\because 1\mathrm{r}\mathrm{e}\mathrm{v}\mathrm{o}\mathrm{l}\mathrm{u}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}=2\mathrm{\pi }\mathrm{radians}\right) \\ =8\mathrm{\pi }\mathrm{radians}\mathrm{per}\mathrm{second} \end{gathered}$$