Kuiz Fizik Tingkatan 5 Bab 4

SELAMAT DATANG Kuiz Fizik Tingkatan 5 Bab 4

KUIZ INI MENGANDUNGI 10 SOALAN

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?

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.

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

Directly above the wire, regardless of field direction

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 electrical resistance of the conductor.

The strength of the current flowing in the conductor.

The total magnetic flux contained within the coil.

The rate of change of magnetic flux through the conductor.

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?

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.

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.

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 Left-Hand Rule

Right-Hand Grip Rule

Lenz’s Law

Fleming’s Right-Hand Rule

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 reduce energy loss due to friction.

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

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

None

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

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

Using a coil with more turns (lilitan).

Replacing the soft iron core with an air core.

Decreasing the current supplied to the coil.

Using weaker permanent magnets.

None

When the north pole of a bar magnet is pushed towards a solenoid, a current is induced. According to Lenz's Law, what will be the magnetic polarity of the end of the solenoid closest to the approaching magnet?

It will have no magnetic polarity.

North pole

South pole

The polarity will alternate rapidly.

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 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.

None

10.

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

Winding the secondary coil on top of the primary coil.

Using thicker copper wires for the coils.

Using a soft iron core instead of a steel core.

Using a laminated soft iron core.

None

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