MEDIUM
AS and A Level
IMPORTANT
Earn 100

This is a circuit.

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Which line in the table shows the changes to the lamp and the voltmeter reading when the temperature rises?

Lamp Voltmeter reading
gets brighter decreases
gets brighter increases
gets dimmer decreases
gets dimmer increases

 

Important Questions on Resistance and Resistivity

EASY
AS and A Level
IMPORTANT

This shows the I-V Characteristic of an electrical component.

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Calculate the resistance of the component when the potential difference across it is  2.0V.

 

EASY
AS and A Level
IMPORTANT

This shows the I-V Characteristic of an electrical component

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Calculate the resistance of the component when the potential difference across it is 5.0V.

 

EASY
AS and A Level
IMPORTANT

This shows the 1-V characteristic of an electrical component

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Suggest what the component is.

 

EASY
AS and A Level
IMPORTANT

A student connects a thermistor to a battery and an ammeter. He places the thermistor in a beaker of water and gradually heats the water from 10°C to its boiling point, recording the value of the current as he does so. He then plots a graph of the current in the thermistor against the temperature of the water

(a) Sketch the graph you would expect the student to obtain from the experiment

EASY
AS and A Level
IMPORTANT

A student connects a NTC thermistor to a battery and an ammeter. He places the thermistor in a beaker of water and gradually heats the water from 10 oc to its boiling point, recording the value of the current as he does so. He then plots a graph of the current in the thermistor against the temperature of the water Explain how the student could now use the thermistor as a thermometer. 

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EASY
AS and A Level
IMPORTANT

 Describe the difference between the conduction processes in copper and in silicon, a semiconductor.

 

EASY
AS and A Level
IMPORTANT

Explain why the resistance of a metallic conductor increases with temperature while that of a semiconductor decreases.

 

EASY
AS and A Level
IMPORTANT

A nichrome wire has a length of 1.5m and a cross-sectional area of0.0080mm2.. The resistivity of nichrome is 1.30×10-8nm.

Calculate the resistance of the wire.