# Problem 1 on current electricity

1. Aug 10, 2010

### anshuiit

1. The problem statement, all variables and given/known data

the problem is attached to this post

2. Relevant equations

Req=1/R1+1/R2+..... for parallel and Req.=R1+R2+... for series... Kirchoff's law for Current and Potential to be applied

3. The attempt at a solution
completely lost ... pls help

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2. Aug 10, 2010

### N-Gin

First you need to find current and voltage across $R_{2}$ as a function of time. Then you can find the generated heat by using the formula

$$W_{2}=\int^{\infty}_{0}V_{2}(t)I_{2}(t)dt,$$

where $V_{2}$ and $I_{2}$ are the voltage and current across resistor $R_{2}$. As you see, time goes from 0 to infinity (when the capacitor is fully charged).

3. Aug 10, 2010

### anshuiit

can u give me the answer???

4. Aug 10, 2010

### N-Gin

It's against the policy! You need to show some effort first.