5.2 Energy storage by capacitors

Question 1

What type of energy can capacitors store?

Answer 1

electric potential energy

Question 2

When do capacitors store energy?

Answer 2

When charge carriers(due to attracton and repulsion at plates) move across a pd supplied by power supply.

Question 3

What is the equation for energy stored by a capacitor?

Answer 3

W  = 1/2QV 
where 
w = work done/energy transferred 
q = charge 
v = pd

Question 4

In a V against Q charge what is the area under the graph?

Answer 4

Work done or energy stored by capacitor?

Question 5

What does a V/Q graph look like for a charging capacitor?

Answer 5

Straight line through the origin,

Question 6

Where does the equation w = 1/2qv come from?

Answer 6

The fact that the area of a V/Q graph is a triangle, since the two are proportional to each other.

Question 7

What is the relationship between q and v of a capacitor?

Answer 7

Theyre proportional , this can be seen from a straight line graph

Question 8

What is the energy stored by a capacitor the same as?

Answer 8

The energy transferred by battery

Question 9

How can we find other equations for energy stored by a capacitor?

Answer 9

Incorporating equation Q = CV and V = Q/V

Question 10

What are the other 2 equations for work done of battery or energy transferred to capacitor?

Answer 10

w = 1/2cv^2 
w = 1/2q^2/c