B - Electricity - Paper 2

Question 1

What is voltage?

Answer 1

V = JC-1volt = joule per coulomb

Question 2

How can you create a static charge?

Answer 2

Rub two insulators together

Question 3

A rod is rubbed by a cloth and gains electrons. Is it positively or negatively charged?

Answer 3

Negatively charged

Question 4

A different rod is rubbed by a cloth and becomes positively charged. Has it lost or gained electrons?

Answer 4

It has lost electrons

Question 5

Give one hazard caused by electrostatic charges and state how the risk from this hazard can be reduced.

Answer 5

1. Risk of a spark causing an explosion (e.g. lorries containing fuel) - reduce risk by ensuring that lorry is earthed
2. Risk of a getting a shock - use insultation, such as wear insulating shoes or use an insulating mat.

Question 6

State one example where static is a nuisance and suggest a solution.

Answer 6

1. Dust attracted to computer or tv screen - use anti-static spray or cloth.
2. Materials clinging to skin - use anti-static cleaner

Question 7

Can you charge a metal rod by rubbing it?

Answer 7

No, because the electrons in metal can flow easily so if electrons were transferred onto the metal rod they would flow away rather than staying on surface of object and making the metal charged.

Question 8

Suggest two useful uses for static electricity in everyday life

Answer 8

2 from

1. Spray Painting
2. Smoke Precipitators
3. Defribrillators

Question 9

There are two types of charge.

Describe how you could demonstrate this using different insulating rods and a cloth.

Answer 9

Method: Suspend the two rods. Rub both rods with a cloth.If they carry the same charge they will be repelled .If they carry different charge they will be attracted.

Question 10

How could you show that a plastic rod gains charge?

Answer 10

1. Try to pick up small peices of paper with it
2. Use it to deflect a stream of water.
3. Try to deflect gold leaf

Question 11

Describe what happens when a plastic rod is rubbed with a cloth.

Answer 11

before rubbing both are neutral

electrons move from the cloth to the rod

plastic rod gains electrons becomes negatively charged

cloth looses electrons becomes positively charged

Question 12

Can rods made of different insulating materials gain a different charge?

Answer 12

Yes, some materials will become positively charged, some will become negatively charged.

Question 13

What happens to something that is negatively charged?

Answer 13

It has gained electrons