Electricity and daily life

Which of the following is the most energy-efficient?

• Incandescent light bulb

• LED light bulb

• Compact fluorescent lamp

When electric current flows through a wire, ________ force is produced.

Which of the following electrical appliances use electricity to produce heat?

• An iron

• An electric fan

• A hairdryer

• A desk lamp

To increase the magnetic force of an electromagnet, we can ________.

• add a magnet close to it

• increase the number of turns in the coil

• increase the length of wire connected to the batteries

• add a switch to the circuit

An electric bell is an example of using _________ to produce sound.

• heat

• electric crane

• electromagnet

• motion

A magnet has _______and ________.

• positive pole

• south pole

• north pole

• negative pole

How are electromagnets different from magnets?

• magnets have south pole and north pole

• magnets are more powerful

• Electromagnets are more convenient to bring along

• You can turn an electromagnets on/off

Which of the following work by producing magnetic force?

• Maglev trains

• Electric fan

• Vacuum cleaner

• Television

The filament in a light bulb produces heat and ________when electricity flows through it.

What is one disadvantage of an electromagnet?

• An electromagnet is a magnet that can be turned off and on

• An electromagnet is much less expensive than a permanent magnet

• An electromagnet is always stronger than a permanent magnet

• An electromagnet needs a power source to operate