Question

The ratio of angular speed of a second-hand to the hour-hand of a watch is

• A. 720:01:00
• B. 60:01:00
• C. 3600:01:00
• D. 72:01:00

Answer 1

Answer: (A)

720:01:00

Answer 2

We know that, angular speed of a watch
$\omega =\frac{\theta}{t}$
$\Rightarrow \omega \propto \frac{1}{t}$
Hence, $\frac{\omega_{\text {sec }}}{\omega_{\text {hour }}} =\frac{t_{\text {hour }}}{t_{\text {sec }}}=\frac{12 \times 3600}{60}=720$
i.e. $\frac{\omega_{ sec }}{\omega_{\text {hour }}}=\frac{720}{1}$