First slide

Alternating current and voltage

Question

A pure resistive circuit element X when connected to an AC supply of peak voltage 200V gives a peak current of 5A which is in phase with the voltage. A second circuit element Y, when connected to the same AC supply also gives the same value of peak current but the current lags behind by 900. If the series combination of X and Y is connected to the same supply, the rms value of current is

Moderate

A

$\frac{10}{\sqrt{2}} A$
B

$\frac{5}{\sqrt{2}} A$
C

$\frac{5}{2} A$
D

5A

Solution

for the first case $\frac{200}{5} = 40 Ω = R$
If current lags by $90^{o}$ it is an inductive circuit: $\frac{200}{5} = 40 Ω = X_{L}$
For series impedance = $Z = \sqrt{X_{L}^{2} + R^{2}} = 40 \sqrt{2}$
$i_{rms} = \frac{200}{\sqrt{2} . 40 \sqrt{2}} = \frac{5}{2} A$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App