# Leaky capacitor

1. Dec 2, 2009

### suryakalpo

1. The problem statement:

A leaky capacitor, Zc =74.5 ohm is in series with a coil Z coil = 40 ohm and a resistor R=50 ohm. When a voltage V=200V is applied I=2.5A and the p.d across R and Z coil is combined is 194V. Find the loss in the capacitor.

2. Relevant equations
Z=(R^2 + (XL - XC)^2)^0.5

3. The attempt at a solution
I have used the impedence eqn for the coil and obtained the inductance and resistance of the coil as r=19.22 ohm and XL = 35.08 ohm

Then I applied the impedence eqn to the entire ckt and obtained the value of Xc = 75.19 ohm.

Now, a leaky capacitor can be represented by a non-leaky capacitor in parallel with a resistance (i hope its right!). But on equating both these capacitive impedences I'm getting an imaginary value of resistance.

I can't figure out where exactly have i gone wrong...if its the theory of the leaky capacitor or mi calculations..plz suggest something

2. Dec 10, 2009

### suryakalpo

guys if u need more clarification abt the question plz let me know

3. Dec 11, 2009