P1 Topic 5 - Generation And Transmission Of Electricity

Question 1

What is electrical power?

Answer 1

Electrical power is the energy transferred per second.

Question 2

What is the equation for power?

Answer 2

Power = current X voltage

Question 3

How does electromagnetic induction work?

Answer 3

Moving a magnet in a coil of wire induces a voltage. As you move the magnet, the magnetic field changes - this induces a voltage, and a current flows in the wire. The direction of the voltage and current depends on which way you move the magnet.

Question 4

What are the four factors that affect the size of the induced voltage and current?

Answer 4

1) The strength of the magnet.
2) The area of the coil.
3) The number of turns on the coil.
4) The speed of movement.

Question 5

How do generators work?

Answer 5

They generate alternating current by electromagnetic induction. Rotating a magnet or rotating a coil of wire and keeping the magnet fixed.

Question 6

What is a dynamo and what does it do?

Answer 6

A dynamo is a particular type of generator which is often used on bikes to power the lights. The magnet is rotated instead of the coil. The dynamo is attached to the wheel - so as the wheel turns, the magnet turns inside the dynamo.

Question 7

What are the four non renewable energy resources?

Answer 7

Coal
Oil
Natural gas
Nuclear fuels - uranium

Question 8

What is the difference between a.c and d.c?

Answer 8

Alternating current keeps changing direction but direct current does not.

Question 9

Non renewable resources?

Answer 9

Coal
Oil
Natural gas
Nuclear fuels

Question 10

Environmental problems with non renewables?

Answer 10

Adds to the greenhouse effect and global warming. Fossil fuels release carbon dioxide. Burning coal and oil releases sulfur dioxide, causes acid rain. Coal mining makes a mess of the landscape. Oil spillages cause environmental problems. Nuclear power waste is very dangerous and disposing is difficult. Nuclear fuel costs a lot to build the power plant. Nuclear power can lead to a catastrophe.

Question 11

Energy changes in a power station?

Answer 11

Chemical energy as fuel goes into the boiler. This becomes heat energy and goes into the turbine. This makes kinetic energy which goes into the generator. This turns it into electrical energy which is sent out to the grid.

Question 12

Hydroelectricity?

Answer 12

Usually involves flooding a valley by building a big dam. The water goes down a pipe through a generator to create electricity.