Question

$L, C$ and $R$ represent the physical quantities inductance, capacitance and resistance respectively. The combinations which have the dimensions of frequency are

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

Answer 1

Answer: (A), (B), (C)

$C R$ and $\frac{L}{R}$ both are time constants. Their unit is second.
$\therefore \frac{1}{C R}$ and $\frac{R}{L}$ have the SI unit (second ) ${ }^{-1}$.
Further, resonance frequency $\omega=\frac{1}{\sqrt{L C}}$