Question

$R,L$ and $C$ represent the physical quantities resistance, inductance and capacitance respectively. Which one of the following combination has dimensions of frequency?

• A. $\frac{1}{\sqrt{RC}}$
• B. $\frac{R}{L}$
• C. $\frac{1}{LC}$
• D. $\frac{C}{L}$

Answer 1

The correct option is B $\frac{R}{L}$

$\frac{L}{R}$ is defined as the time constant of the L-R circuit. So, $\frac{L}{R}$ has the dimension of time.

Thus, $\frac{R}{L}$ has the dimensions of frequency (because frequency is the reciprocal of time).