
This is a circuit.

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
This shows the Characteristic of an electrical component.
Calculate the resistance of the component when the potential difference across it is .

This shows the Characteristic of an electrical component
.
Calculate the resistance of the component when the potential difference across it is

This shows the characteristic of an electrical component
.
Suggest what the component is.

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 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

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.

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

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

A nichrome wire has a length of and a cross-sectional area of. The resistivity of nichrome is
Calculate the resistance of the wire.
