Work done is the area under a voltage against charge graph

[mrcotton]

Homework Statement

Homework Equations

Area of a triangle is 0.5 × b × h
ΔW=VΔQ

The Attempt at a Solution

I drew a straight line graph from the origin with end point 4.5V 9.0 microF
energy is a work done = .5QV


There is a mark in the mark scheme for ΔW=VΔQ explained.

What do you think I need to say for this mark?

any help gratefully received

 

[Redbelly98]

Your physics textbook, and perhaps your class lecture notes, should have an explanation of electric potential and how it relates to charge as well as work or energy. I would take a look at that.

 

[mrcotton]

Hi Redbelly thanks for responding.
I have just read in my notes that the energy stored in the capacitor is equal to the work done to force the extra charge onto the plates.

So ΔE=VΔQ
So V is changing and I guess if we make the increments very small in Q then the areas of each strip under the line add up to the total area under the triangle with base Q and Height V.
Thanks again