Magnetism & Its Uses

The force a magnet exerts on another magnet, on iron or a similar metal, or on moving charges is

• proportional to the mass of the magnet.

• a magnetic force.

• an electric force.

• proportional to the charge of the magnet.

The output voltage and current of a transformer are determined by the

• direction of the current in the primary coil.

• strength of the DC current in the primary coil.

• number of turns in the primary and secondary coils.

• ferromagnetic material of the rings connecting the coils.

A coil of wire that is carrying a current and produces a magnetic field is called a(n) __.

• electric motor

• solenoid

• galvanometer

• transformer

The electromagnet in a galvanometer

• increases the current in a circuit.

• moves a pointer along a numbered scale in response to a current.

• increases the voltage in a circuit.

• induces an electric current.

If a step-up transformer has a primary coil with 15 turns, how many turns would be required in the secondary coil in order to increase voltage from 80 V to 160 V? Use T2 = (V2 x T1) / V1.

• 160 turns

• 30 turns

• 7.5 turns

• 853 turns

The region around a magnet that exerts a magnetic force is called __.

• magnetic poles

• magnetic field

• auroras

• electric field

The region where a magnet's force is the strongest is called the __.

• electric field

• magnetic field

• auroras

• magnetic poles

A brilliant, colorful display caused by charged particles from the sun entering the Earth's magnetic field are called __.

• auroras

• magnetic poles

• electric field

• magnetic field

A ferromagnetic material that has domains that remain aligned for a long period of time is called __.

• a permanent magnet

• nonmagnetic

• a temporary magnet

• a neutral object

In the figure, starting from the LEFT, what magnetic poles (IN SEQUENCE to the RIGHT) are shown on the two bar magnets?

• NORTH, SOUTH, SOUTH, NORTH

• SOUTH, NORTH, NORTH, SOUTH

• NORTH, SOUTH, NORTH, SOUTH

• SOUTH, NORTH, SOUTH, NORTH