Kuiz Fizik Tingkatan 5 Bab 4

SELAMAT DATANG Kuiz Fizik Tingkatan 5 Bab 4

KUIZ INI MENGANDUNGI 10 SOALAN

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

To prevent the transformer from overheating during operation.

To step down the current while stepping up the voltage.

To provide electrical insulation between the primary and secondary coils.

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

None

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

Replacing the soft iron core with an air core.

Using a coil with more turns (lilitan).

Decreasing the current supplied to the coil.

Using weaker permanent magnets.

None

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

Using a soft iron core instead of a steel core.

Using thicker copper wires for the coils.

Using a laminated soft iron core.

Winding the secondary coil on top of the primary coil.

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?

200 turns

12.5 turns

50 turns

800 turns

None

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

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

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

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

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

None

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

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

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

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

DC current is unable to magnetize the 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?

Right-Hand Grip Rule

Fleming’s Right-Hand Rule

Lenz’s Law

Fleming’s Left-Hand Rule

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 total magnetic flux contained within the coil.

The strength of the current flowing in the conductor.

The electrical resistance of the conductor.

The rate of change of magnetic flux through the conductor.

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.

Directly above the wire, regardless of field direction

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

None

10.

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

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

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

To increase the strength of the magnetic field.

To reduce energy loss due to friction.

None

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