Electromagnetism

A voltage is induced in a conductor when it moves across the lines of magnetic flux of a magnetic field.

• False

• True

Inductors with an air core have a higher value of inductance that those with an iron core.

• True

• False

• Only if the iron core is laminated

If the polarity of the magnet is changed by swapping the north and south poles, the polarity of the induced voltage in a conductor moving through it will also change.

• True

• False

• True, but only if the conductor moves at right angles to the field

All practical inductors have some resistance.

• True

• False

When a conductor is moving in a given direction within a magnetic field, Fleming’s right-hand rule determines the direction of the:

• induced EMF

• magnetic north

• force produced

• flux density produced

If you increase the speed of a conductor passing through a magnetic field, the induced voltage will:

• halve

• decrease

• increase

• remain the same

Inductor cores used with an alternating current require:

• laminations

• longer lengths

• increased cooling

• greater cross-sectional areas

If you triple the effective length of a conductor passing through a magnetic field, the voltage produced will:

• increase slightly

• remain the same

• triple

• double

The three main types of inductor cores are air, soft iron and:

• copper

• hard iron

• stainless steel

• ferrite

The process by which one coil induces a voltage in another adjacent coil is called:

• variable inductance

• moving inductance

• mutual inductance

• self inductance