Magnets Practice 1

Which of the following statements about the properties of magnets is incorrect?

• Has a magnetic field around it

• Has two opposite poles - North and South

• Will attract magnetic materials

• Will attract non-magnetic materials

All strongly magnetic materials contain iron, nickel, or cobalt. What is the other terminology for strong magnetic materials?

• Alcomax

• Ferromagnetics

• Mumetal

• Magnadur

A student suggests three methods for demagnetizing a piece of steel.

1. Placing it in east-west direction and hammering it hard.
2. Placing it in east-west direction and heating it until red-hot.
3. Removing it slowly from a coil carrying alternating current.

Which of the methods will demagnetize the piece of steel?

• 1 only

• 2 only

• 3 only

• 1, 2 and 3

What is the most effective method of demagnetizing a bar magnet?

• Placing the magnet in a solenoid carrying a large alternating and gradually decreasing the current.

• Placing the magnet in a solenoid carrying a large direct current and gradually decreasing the current.

• Placing the magnet in a solenoid that produces a magnetic field in the opposite direction to the magnet.

• Placing the magnet next to an identical bar magnet with its poles in the opposite direction.

Choose all the non-magnetic materials listed below.

• Brass

• Copper

• Nickel

• Cobalt

Choose the correct statement (s) listed below.

• Magnetic field exists around magnet and exerts forces on magnetic materials in it.

• The magnetic field lines run from the S poles to the N poles of the magnet.

• Magnetic fields can be investigated using a small compass.

• The magnetic field is strongest where the field lines are closest together.

What is the name of position x in the picture?

• Magnetic field

• Magnetic north

• Neutral point

• Magnetic south

The Earth has a magnetic field. Where is the location of the Earth's magnetic S pole?

• South pole

• North pole

• Equator line

• Everywhere on Earth

In the right-hand grip rule, your thumb points in the ....

• direction of field lines

• electron movement

• conventional current direction

• electric field

The strength of magnetic field in a wire increases when ...

• the current flow increases

• the electric field increases

• there is no barrier between the wire and magnet

• it is close to the wire