Required Practical 2✔️ (resistance)

Question 1

What is the aim of the experiment?

Answer 1

To investigate how changing the length of the wire affects its resistance

Question 2

Explain steps 1 and 2 of the method?

Answer 2

1) set up the circuit and then attach a crocidile clip at 0cm and then the second clip at 10cm and write down the length in between

2)close the switch - then record the reading on the ammeter and on the voltmeter

Question 3

Explain steps 3 and 4 of the method?

Answer 3

3)open the switch - then move the crocidile switch another 10cm along the wire and close the switch and record readings on ammeter and voltmeter

4)repeat the previous steps increasing the length of the wire by 10cm each time up to 100cm

Question 4

Explain the final step 5 of the method?

Answer 4

5)use the results to caculate the resistance of each length of wire, by using R = V/I - then plot a graph using the results

Question 5

What is a hazard with the experiment and a control measure?

Answer 5

• heating of the resistance wire - which would burn your skin so do not touch the resistance wire while the circuit is connected and allow it to cool

Question 6

What is the dependent variable?

Answer 6

Readings on the ammeter and voltmeter then using the equation R = V/I

Question 7

What is the independent variable?

Answer 7

• distance between crocidile clips

Question 8

What are the control variables?

Answer 8

• type of wire
• voltage of the power supply

Question 9

What does the voltmeter do?

Answer 9

Measures the potential difference across the wire - must be placed in parallel around whatever your investigating in this case the wire

Question 10

what does the ammeter do?

Answer 10

Measures the current flowing through the wire - must be placed in series with whatever your investigating

Question 11

Give a list of the equipment needed?

Answer 11

• ammeter
• voltmeter
• wire
• x2 crocidile clips
• 1m stick
• circuit