PAG 9.3 Investigating Capacitance

Question 1

What equation links the area and separation of a capacitor’s plate to its capacitance?

Answer 1

C = ε0A/d

Question 2

What is ε0 and what are its units?

Answer 2

ε0 is the permittivity of free space and it is measured in Farads per meter
ε0 = 8.85 x 10^-12

Question 3

If the area of the plates of a capacitor is increased, how would the capacitance change?

Answer 3

Area of the plates and capacitance are directly proportional, so capacitance would increase

Question 4

If the separation of the plates of a capacitor is increased, how will the capacitance change?

Answer 4

The separation of the plates and capacitance are inversely proportional, so capacitance will decrease

Question 5

How can the area of the plates be altered in this experiment

Answer 5

Area we measure in this experiment is the area over which the plates overlap
This means that to change this area, we can slide one of the plates to the side causing area to change

Question 6

How can the overlap area be obtained from the length over which the plates overlap?

Answer 6

Length over which the plates overlap can be multiplied by the width of the plates to obtain area

Question 7

How can capacitance in each arrangement be measured?

Answer 7

Multimeter

Question 8

How can a multimeter be connected to the aluminium plates?

Answer 8

Crocodile clips can be clipped onto the aluminum plates and these leads can be plugged into the multimeter

Question 9

How could a systematic error in your overlapping area measurements occur?

Answer 9

Widths are not perfectly aligned

Question 10

What is capacitance?

Answer 10

Measurement of how much electric charge can be stored per unit potential difference across it.