Question

By what percentage the impedence in an AC series circuit should be increased so that the power factor changes from (1/2) to (1/4) (when R is constant)?

• A. 200%
• B. 100%
• C. 50%
• D. 400%

Answer 1

The correct option is B 100%

Percentage $=\frac{z_2-z_1}{z_1}\times 100$

$=\frac{4R-2R}{2R}\times 100$

$=100$%