# Scaling factor of Energy in a capacitor with change in charge

1. Jan 9, 2013

### mrcotton

1. The problem statement, all variables and given/known data
AQA Section A Q18 Jun 11

2. Relevant equations

E=.5QV and C=Q/V
3. The attempt at a solution

So the original Q has increased by 1.5 times If C is constant than the voltage must also increase by 1.5 times

Now the energy E is E=.5QV V has increase by 1.5 and and so has Q which is 2.25

Infact in typing this out I think I just solved it. Is this logic and method ok

2. Jan 9, 2013

### Dick

Seems fine to me.

3. Jan 10, 2013

### jfgobin

Yup. You may recall that the energy stored in a capacitor is also given by:

$E = \frac{1}{2}CV^2$