Practical electricity

Question 1

WHAT are the heat effects of electricity

Answer 1

convert electrical energy into heat

Question 2

What is formulas to find power

Answer 2

p=iv
p=i2 r
p=v2/r

Question 3

How to find energy

Answer 3

E=pt

Question 4

Formula for cost of using electrical appliance

Answer 4

kwh=p x t (h)
cost= kwh cost x kwh energy

Question 5

Types of electrical hazards

Answer 5

damaged insulation - can cause short circuit and electrocution
overloading and overheating of cables - can cause damage to appaliance and fire
Damp conditions - cause electrocution

Question 6

types of safety device

Answer 6

Fuse - when current exceed rated value, will blow and break circuit. protect appliance from overheating
circuit breaker - current exceeds circuit breaking rating, trips to isolate the appliance from the mains to protect the equipment and cable from overheating.
earthing
double insulation
earthing - fault causes the metal casing to be live and earth wire provide low res path for current to flow to the earth instead of the user

It will draw a large current from the lives wire thus causing fuse to blow and isolate appliance from the mains

Question 7

What is connected to the live wire

Answer 7

fuse switches and circuit breaker
sothat they can isolate electrical appliance from high voltage mains

Question 8

What colour is the live wire and function

Answer 8

brown
Carries high voltage , allow current from the source to reach appliance

Question 9

What colour is the neutral wire
and function

Answer 9

blue
carries 0V, allow current to return to source to complete the circuit

Question 10

What colour is earth wire

Answer 10

green and yellow
0v Acts as safety device