Year 8 Magnetic Fields, Electromagnets, Earth's Magnetic Field

What factors can change the strength of an electromagnet?

• Color of the wire, length of the wire
• Number of turns in the coil, current flowing through the coil, material of the core, presence of a soft iron core
• Temperature of the room, humidity level
• Shape of the coil, type of power source

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Why does the Earth have a magnetic field?

• Due to the presence of large mountains

• Because of the rotation of the Earth

• As a result of the core acting as a magnet

• Because of the gravitational pull of the moon

What is a magnetic field?

• A type of metal that attracts other metals

• An invisible area surrounding a magnet where magnetic forces are experienced

• A type of electrical circuit that generates light

• A type of rock found deep within the Earth's crust

Tags

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What role does the Earth's magnetic field play?

• It controls the Earth's temperature.

• It shields the Earth from harmful solar radiation.

• It determines the Earth's rotation speed.

• It creates the Earth's atmosphere.

How can you make an electromagnet?

• By heating a piece of metal

• By wrapping a wire around an iron nail and passing electric current through the wire

• By exposing a metal object to sunlight for a prolonged period

• By placing a magnet near a piece of copper wire

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What is one application of electromagnets?

• Cooking food in a microwave oven

• Sending signals through fibre optic cables

• Generating electricity in a solar panel

• Lifting heavy objects in a junkyard

How does increasing the number of wire coils affect the strength of an electromagnet?

• It weakens the magnetic field.

• It has no effect on the strength of the magnetic field.

• It strengthens the magnetic field.

• It changes the colour of the magnetic field.

What part of the Earth acts as a magnet?

• The crust

• The mantle

• The outer core

• The inner core