P6a - Resisting

Question 1

What is a resistor?

Answer 1

Something the reduced the flow of the current.

Question 2

How does a variable resistor work?

Answer 2

It contains a long length of wire, so that the length of wire that is connected into the circuit can be changed.

Question 3

How do you calculate resistance?

Answer 3

Resistance = voltage/current

Question 4

What causes resistance?

Answer 4

It is caused by the electrons bumping into atoms. They cause the atoms to vibrate more. This in turn causes more collisions. The temperature also rises and when the wire becomes very hit, the increased motion of the atoms due to the high temperature means that there are more collisions. It become more difficult for the current to flow through the conductor, causing resistance.

Question 5

What is an electrical current?

Answer 5

A flow of charged carriers. In metals these charged carriers are electrons.

Question 6

Describe how a variable resistor cans be used to make a bulb dimmer?

Answer 6

The resistance would need to be increased do that the current is less. This would be done by increasing the length of wire connected into the circuit.