Question

For the series LCR circuit shown in the figure, what is the resonance frequency and the amplitude of the current at the resonating frequency

• A. $2500rad - s^{- 1}$ and $5\sqrt{2}A$
• B. $2500rad - s^{- 1}$ and $5A$
• C. $2500rad - s^{- 1}$ and $\frac{5}{\sqrt{2}}A$
• D. $25rad - s^{- 1}$ and $5\sqrt{2}A$

Answer 1

Answer: (B)

$2500rad - s^{- 1}$ and $5A$

Answer 2

Resonance frequency

$\omega = \frac{1}{\sqrt{LC}} = \frac{1}{\sqrt{8 \times 10^{- 3} \times 20 \times 10^{- 6}}} = 2500\mspace{6mu} rad/\sec$

Resonance current = $\frac{V}{R} = \frac{220}{44} = 5A$