In the circuit shown in figure power factor of box is `0.5` and power factor of circuit is `sqrt3/2` .Current leading the voltage. Find the effective resistance of the box.

Options

A. `5Omega`
B. `10Omega`
C. `15Omega`
D. `20Omega`

Answer

A

Explanation

`(1)/(2)=(R )/(sqrt(R^(2)+X_(c).^(2)))`
`sqrt(3)/(2)=(R+10)/(sqrt((R+10)^(2)+X_(C)^(2)))`
Solving these two equation
`R=5Omega`