Kuiz Fizik Tingkatan 5 Bab 4

SELAMAT DATANG Kuiz Fizik Tingkatan 5 Bab 4

KUIZ INI MENGANDUNGI 10 SOALAN

What is the key structural difference in the way the coil connects to the external circuit in an AC generator versus a DC generator?

A DC generator uses permanent magnets, while an AC generator must use electromagnets.

An AC generator has more coil turns than a DC generator.

An AC generator uses slip rings, while a DC generator uses a split-ring commutator.

The coil rotates clockwise for AC output and counter-clockwise for DC output.

None

What is the primary function of the split-ring commutator in a direct current (DC) motor?

To increase the strength of the magnetic field.

To connect the motor to an alternating current (AC) supply.

To reverse the direction of the current in the coil every half rotation.

To reduce energy loss due to friction.

None

The force on a current-carrying wire in a magnetic field results from a 'catapult field'. In which region of this resultant field is the magnetic field weakest?

Where the field lines from the wire and the permanent magnet are in the same direction.

Along the central axis of the permanent magnet’s field.

Where the field lines from the wire and the permanent magnet are in opposite directions.

Directly above the wire, regardless of field direction

None

Which of the following changes would increase the rate of rotation of a DC electric motor?

Decreasing the current supplied to the coil.

Using a coil with more turns (lilitan).

Using weaker permanent magnets.

Replacing the soft iron core with an air core.

None

Which modification would most effectively increase a transformer's efficiency by reducing energy loss from eddy currents?

Using thicker copper wires for the coils.

Using a soft iron core instead of a steel core.

Winding the secondary coil on top of the primary coil.

Using a laminated soft iron core.

None

Which of the following rules is used to determine the direction of the force experienced by a straight wire carrying a current within a magnetic field?

Fleming’s Right-Hand Rule

Fleming’s Left-Hand Rule

Right-Hand Grip Rule

Lenz’s Law

None

An ideal step-up transformer is designed to change a 12 V input to a 48 V output. If the primary coil has 50 turns, how many turns must the secondary coil have?

12.5 turns

200 turns

50 turns

800 turns

None

What is the primary purpose of the soft iron core in a transformer?

To concentrate and guide the magnetic flux from the primary to the secondary coil.

To step down the current while stepping up the voltage.

To prevent the transformer from overheating during operation.

To provide electrical insulation between the primary and secondary coils.

None

According to Faraday's Law of Induction, the magnitude of the induced electromotive force (e.m.f.) in a conductor is directly proportional to what?

The rate of change of magnetic flux through the conductor.

The electrical resistance of the conductor.

The strength of the current flowing in the conductor.

The total magnetic flux contained within the coil.

None

10.

Why will a transformer not operate if its primary coil is connected to a direct current (DC) power supply?

The secondary coil is designed in a way that only allows alternating current to be generated.

The resistance of the primary coil is too high for DC to flow.

DC current is unable to magnetize the soft iron core.

A DC supply produces a constant magnetic field, which does not induce a current in the secondary coil.

None

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