Physics Paper 2 Practical Resistance

Question 1

Method of resistance practical

Answer 1

• attach a wire to a meter ruler using tape
  Connect wire to the circuit using two crocodile clips
  Only the part which is between the crocodile clips is connect to circuit
  Now move the crocodile clips further apart to increase length of the wire as this increases the resistance
  Change the length of the wire and measure the resistance in the circuit
  U get a straight line passes through zero - resistance dp to length

Question 2

Errors zero

Answer 2

Small resistance when length - 0 - shouldn’t be there - it’s a problem - zero error

Why - some resistance cause by contact between clip and wires

Question 3

Heating effects

Answer 3

If temp of wire increases - resistance will also increase

Using a low P.D will keep current low reducing heating

• only turn current on when taking a reading.
  Turn it off between readings.

Question 4

Variable resistor

Answer 4

Contains a king piece of wire in a coil. Use a slider to change the length. It can control the p.d across the circuit.