Physics Practicals 1

Question 1

Practical one: Resistance. (equipment)

Answer 1

• Battery.
• Ammeter.
• Voltmeter.
• Length of wire.

Question 2

What is the purpose of such pratical?

Answer 2

• How the resistance depends on the length of the wire.

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Question 3

How to do we change the length of the wire?

Answer 3

• Place the wire onto a meter ruler using tape and attach it to the circuit using crocodile clips.
• ## We can move the crocodile clips fruther apart to increase the length of the wire.

Question 4

What does the graph look like?

Answer 4

• ## Resistance of a wire is directly porportionate to the length.

Question 5

Problems with the praticle?

Answer 5

• Small resistance when length is 0.
• Not a result but a problem with the method.
• Zero error
• Difficult to adjust the crocodile clip to 0.
• There may be some resistance caused by the contact between the crocodile clips and the wire. We can’t do anything.

Question 6

What is a 0 error?

Answer 6

• A zero error is a reading on a measuring instrument when the values should be zero.
• Systematic error + can not be reduced by repeating the experiment.
• Need to subtract the error from all the readings.

Question 7

What are the heating affects of the practicle?

Answer 7

• If the temperature of the wire increases: resistance increases.
• Reduce this?
• Lower potential difference, keep the current low and reduce heating in wire.
• Turn the current when taking a reading and turn current between readings.

Question 8

What is a variable resistor?

Answer 8

• Contains a long piece of wire and a coil.
• ## Using slider change the length of wire current runs through.