Capacitors CGP pg 132

Question 1

Capacitors build up… On plates

Answer 1

Charge

Question 2

A Capacitor is a

Answer 2

And electrical component made up of two conducting plates separated by a gap or a dielectric ( an insulating material )

Question 3

When a capacitor is connected to a power source ..creating..

Answer 3

Positive and negative charge build up on opposite plates

creating a uniform electric field between them

Question 4

What capacitance

Answer 4

The Amount of charge per unit potential difference stored by a capacitor

Question 5

C=

Answer 5

Q/V

Question 6

U can increase capacitance using

Answer 6

Dielectrics

Question 7

Permittivity is a measure of

Answer 7

How difficult it is to generate an electric field in a certain material

Question 8

The relative permittivity is the

Answer 8

Ratio of the permittivity of a material to the permittivity of free space

Question 9

Relative permittivity is sometimes also called the

Answer 9

Dielectric constant

Question 10

Imagine a dielectric is made up of lots of polar molecules -(they have a positive end and a negative end)

When no charge is stored by the capacitor there is ..
So these molecules..

When a charge is applied to a capacitor an …is generated

The negative ends of the molecules are attracted to the…and vice versa

This causes all of the molecules to …and align themselves with …

The molecules each have their own electric field which in this alignment now opposes the..

The larger the permittivity,the larger this..

This reduces the…which reduces the ..

Answer 10

No electric field

-so these molecules point in a bunch of random directions

Electric field

The positively charged plate

Rotate

The electric field

Applied electric field of the capacitor

Opposing field is

Overall electric field

Potential difference needed to charge the capacitor -so the capacitance increases

Question 11

You can calculate the capacitance of a capacitor using the …capacitor and the permittivity of the ..

Answer 11

Dimensions

Dielectric

Question 12

Capacitors store

Answer 12

Energy

Question 13

When charge builds up on the plates of a capacitor ,..

Answer 13

Electrical energy is stored by the capacitor

Question 14

You can find the energy stored in a capacitor from the…

Answer 14

Area under the graphOf charge stored against potential difference across the capacitor

Question 15

The potential difference across the capacitor is … To the charge stored on it

Therefore the growth of charge stored against potential difference will be a…

Answer 15

Directly proportional

Straight line through the origin

Question 16

By looking at the graph of charge stored against potential difference we can see thatThe greater the capacitance the more energy is stored by the capacitor for a given…

Answer 16

Potential difference

Question 17

The energy stored in a capacitor (joules) is equal to

Answer 17

Half Q times V