P2 - Resistance and V=IR (2)

Question 1

What is the equation that links Potential Difference, Current and Resistance together?

Answer 1

V=IR

V=PD I=Current R=Resistance

Question 2

What does the Ammeter do in a circuit?

Answer 2

The ammeter measures the current flowing through a circuit.

Question 3

What type of circuit should the Ammeter be placed in?

Answer 3

They should always be placed in series.

Question 4

What does the Voltmeter do in a circuit?

Answer 4

The voltmeter measures the potential difference across the circuit.

Question 5

What type of circuit should the Voltmeter always be placed in?

Answer 5

It should always be parallel to whatever you are investigating.

Question 6

What is the Test Wire and Crocodile Clip Practical and say what happens.

Answer 6

1) Attach a crocodile clip at 0cm on the ruler.
2) Attach the second clip to the wire around 10cm away from the first clip
3) Close the switch and record the current through the wire and the PD across it.
4) Open the switch then move the clip another 10cm away from the first clip.
5) Close the switch and record everything again.
6) Repeat this for a number of different lengths of the test wire.
7) Use your meeasurements of Current and PD and calculate the Resistance using V=IR
8) Plot a graph of resistance against the wire length and draw a line of best fit
9) The line should be straight through the origin

Question 7

What is the rule of this experiment?

Answer 7

The longer the wire the greater the resistance.

Question 8

What does Directly Proportional mean

Answer 8

It means the resistance is directly proportional to the length.