Domestic electricity

Question 1

What are ring circuits?

Answer 1

Circuits where power travels both ways around the cricuit are a ring circuict. Sockets are usually connect this way, so that if one has a fault, there rest will still work. Ring circuits have a common neutral and fuse.

Question 2

What are radial circuits?

Answer 2

Radial circuits are ciruicts that radiating directly from the distrbution box. They are genreally used from appliances that uses a large amount of power e.g cooker, shower etc

Question 3

Are lighting circuits connected in series or paralell

Answer 3

They are connected in paralell so that idividual faults do not cause the circuit to fail

Question 4

What ae fuses?

Answer 4

Fuses are connected in the live and are used to prevent to much current flowing through a circuit.Since current has a heating effect, too much current will cause the fuse to melt and break the circuit. The value of a fuse should be slightly higher than the expected current.

Question 5

What are MCBs?

Answer 5

Mincature Circuit breakers (MCBs) are essentially resettable fuses. The live wire is wrapped around an iron core making it an electromagnet. When too much current is present, it is pulled againist a switch breaking the circuit. (The switch is levered againtist a spring so it tales a preset current to pull it away)

Question 6

What are RCDs

Answer 6

Residual circuit breakers (RCD) acts like a transformer. The live and neutral wires opposite sitdes of an iron core like the wires in a transfomer. A.C flows back and forth through the live wire inducing a magentic field. At the same time, an A.C flows back and forth through the neutral wire, inducing an oppopsite magnetic field to the live wire. The magnetic fields cancel out. However should there be a fault and the current flowing through either of the two wires is no the same, a magnetic field will exist which will

Question 7

In a plug, what colour are the wires and what side are the wires connected to?

Answer 7

• The Live(Brown) is connected to the fuse on the right
• Neutral(Blue) is connected to the left
• The earth(green and yellow) is connnected to the middle

Question 8

What is the kilowatt hour?

Answer 8

The amount of energy a 1000W aplliance uses in one hour