Question

A microwave oven rotates with angular speed $2\omega$ and initial frequency $f_i$. If angular speed decreases to $\omega$, final frequency $f_f$ of the rotor is

• A. $\frac{3f_i}{2}$
• B. $\frac{f_i}{2}$
• C. $\frac{f_i}{4}$
• D. $\frac{f_i}{3}$

Answer 1

The correct option is B $\frac{f_i}{2}$

The relation between angular velocity and frequency is given as,
$\omega =2\pi f$

$\frac{{\omega }_i}{{\omega }_f}=\frac{f_i}{f_f}$
$\frac{2\omega }{\omega }=\frac{f_i}{f_f}$
$f_f=\frac{f_i}{2}$