Electricity Magnetic and Heating Effects

Which of the following is the safest practice while using electricity?

1. Overloading sockets
2. Touching exposed wires
3. Switching off the power before repairing an appliance
4. Pulling a plug by its wire

Why should electrical appliances never be handled with wet hands?

1. Water improves electrical conductivity.
2. Wet hands increase the risk of electric shock.
3. Wet hands cool the appliances.
4. Nothing happens.

Which effect of electric current is used in an electric motor?

1. Heating effect
2. Magnetic effect
3. Chemical effect
4. Cooling effect

Which device uses an electromagnet to produce sound?

1. Electric bell
2. Torch
3. Candle
4. Solar cooker

Which of the following increases the strength of an electromagnet?

1. Reducing the number of turns in the coil
2. Increasing the number of turns in the coil
3. Removing the iron core
4. Using plastic instead of iron

What is meant by a short circuit?

1. Normal flow of electricity
2. Current flowing through an unintended low-resistance path
3. Weak battery
4. High resistance in a wire

What is the main purpose of an electric fuse?

1. Increase current
2. Produce light
3. Protect appliances from excessive current
4. Store electricity

Which safety device protects electrical circuits from excessive current?

1. Switch
2. Fuse
3. Bulb
4. Cell

Which material is commonly used to make the heating element of electric appliances?

1. Aluminium
2. Copper
3. Nichrome
4. Plastic

Which appliance mainly works on the heating effect of electric current?

1. Electric fan
2. Electric iron
3. Loudspeaker
4. Electric motor

Which material is generally used as the core of an electromagnet?

1. Plastic
2. Soft iron
3. Copper
4. Wood

Who discovered the magnetic effect of electric current?

1. Isaac Newton
2. Hans Christian Oersted
3. Albert Einstein
4. Galileo Galilei

Which instrument is used to detect the magnetic effect of electric current?

1. Thermometer
2. Compass needle
3. Barometer
4. Stopwatch

What happens when electric current flows through a wire?

1. The wire becomes lighter.
2. The wire shows magnetic and heating effects.
3. The wire disappears.
4. The wire stops conducting electricity.