| Question | Answer |
|---|---|
| What type of circuit can be found in the home | Ring circuit |
| How are lighting and ring circuits, series or parallel | Parallel |
| what do you call a thin piece of wire that heats up and melts when a current above a certain value passes through it | Fuse |
| If a circuit has a current of 7A passing through it, what fuse should be used | 10A |
| What do you call the modern devices that house use now instead of fuses | Circuit breakers |
| What colour is the positive live wire | Brown |
| What colour is the negative neutral wire | Blue |
| What colour is the earth wire | Green and Yellow |
| What is the purpose of the earth wire | It is a safety wire that carries live current to the ground if required |
| Why should you never overload a circuit | can cause a fire |
| What is the unit of electrical power | watt (W) |
| What is the watt a measure of | How quickly an appliance converts electrical energy to other forms of energy |
| What is the ESB unit of electricity | kilowatt hour (kWh) |
| How would you calculate the number of kilowatt hours used | Number of kilowatts * number of hours |
| How would you calculate the cost of electricity | Number of units * cost per unit |
| What is a direct current (d.c.) | current that travels in one direction only |
| What is an alternating current (a.c.) | Current that changes direction many times per second, like the ESB supply |
| How can alternating current be converted to direct current | Using a rectifier |
| If an immersion heater has a power rating of 2000W, what is it rating in kW | 2kW |
| If a 2kW heater is left running for 6 hours, how many units of electricity does it use | 12units |
| If electricity costs 15c per unit, what does it cost to run the heater that uses 2 units every hour, if it is running for 6hours | 0.15x2x6= 1.80 |
