Question

If the resistor is doubled and the inductor is halved what happens to the final current after the switch is closed?

1. It decreases by a factor of 4
2. It decreases by a factor of 2
3. It remains the same
4. It increases by a factor of 2
5. It increases by a factor of 4

0000

Answer 1

(1) Assuming, initial resistance and inductance of circuit is R and L. therefore,

new Resistance R' = 2R

new inductance of inductor L' = 0.5L

Current through RL circuit is given by;

$I=\frac{V}{\sqrt{R^2+w^2L^2}}$

new Current;

$I'=\frac{V}{\sqrt{(2R)^2+w^2(0.5L)^2}}$

cannot be determined without actual values.