Electricity & Energy Check Test

What type of energy is produced from burning gas in a power station?

• Heat energy

• Electrical energy

• Kinetic energy

• Nuclear energy

Answer explanation

There is chemical energy in the gas. When it is burned it releases heat energy.

What drives a turbine in a power station?

• Wind
• Electricity
• Coal
• Steam

Answer explanation

The heat energy turns the water to steam and the steam then passes through the fans in the turbine and makes the fan blades turn.

What is the power rating of this food steamer?

• The power rating of the food steamer is 1 kilowatt.
• The power rating of the food steamer is 1000 watts.
• The power rating of the food steamer is 900 watts.

• The power rating of the food steamer is 500 watts.

Answer explanation

You need to read the label to find the answer. You are looking for a number with a W after it. The W stands for Watts and this is the unit for electrical power.

Which of these 4 factors will affect the cost of using the heater the most?

• Brand of the heater
• Color of the heater
• The fuse rating

• How long it is switched on

Answer explanation

You use Energy = Power x Time. The cost is based on the amount of energy the device uses, which is calculated by multiplying the power rating (which does not change) by the time it is switched on. The longer it is one for, the more energy it uses.

When drawing magnetic field lines, the direction of the magnetic field goes from north to south.

• True

• False

Answer explanation

The magnetic field lines always go from north to south. The lines must touch the magnet and use a ruler to draw any straight lines.

What 3 parts are labelled in this diagram of a transformer?

• Primary coil, Secondary coil, Iron core
• Input coil, Output coil, Copper core
• Primary winding, Secondary winding, Aluminum core
• Copper wire, Tertiary coil, Steel core

Answer explanation

The primary coil is connected to the input. The secondary coil is connected to the output. Both coils are wrapped around an iron core.

Which of these are not a digital component?

• Motor
• Solenoid
• Relay
• 7 segment display

• LED

Answer explanation

7 Segment display, LED, Solenoid & Relay are all digital components. Motor is an analogue component.

Which of the following appliances produces the most heat energy in 5 minutes?

• Cooker (12000W)

• Drill (800W)

• Iron (1250W)

• Kettle (2400W)

Answer explanation

You need to look at the power rating and purpose of each appliance. The one that produces heat energy and has the largest power rating, is the one that produces the most heat.

How do you connect an ammeter?

• Connect the ammeter in parallel with the load or component where you want to measure the current.
• Connect the ammeter to a power source directly.
• Connect the ammeter in series with the load or component where you want to measure the current.
• Connect the ammeter to a random point in the circuit.

Answer explanation

Ammeters have to be connected in series.

How do you connect a voltmeter if you are measuring the voltage of a lamp?

• In parallel with the lamp
• In series with the lamp
• Touching the lamp
• Connecting to the ground

Answer explanation

Voltmeters have to be connected in parallel