Kuiz Fizik Tingkatan 5 Bab 4

SELAMAT DATANG Kuiz Fizik Tingkatan 5 Bab 4

KUIZ INI MENGANDUNGI 10 SOALAN

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 strength of the current flowing in the conductor.

The rate of change of magnetic flux through the conductor.

The electrical resistance of the conductor.

The total magnetic flux contained within the 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.

Using weaker permanent magnets.

Decreasing the current supplied to the coil.

None

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

To provide electrical insulation between the primary and secondary coils.

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.

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?

South pole

North pole

It will have no magnetic polarity.

The polarity will alternate rapidly.

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.

DC current is unable to magnetize the soft iron core.

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

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?

Lenz’s Law

Fleming’s Left-Hand Rule

Fleming’s Right-Hand Rule

Right-Hand Grip 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 reverse the direction of the current in the coil every half rotation.

To reduce energy loss due to friction.

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

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 has more coil turns than a DC generator.

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

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

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

None

In a simple DC motor, the coil continues to rotate past the vertical position even though the current is momentarily cut off. What is the reason for this continued rotation?

The magnetic field from the permanent magnets reverses.

The rotational force on the coil sides is at its maximum.

The coil’s rotational inertia.

The power supply provides a brief surge of current.

None

10.

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 the same direction.

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

Directly above the wire, regardless of field direction

None

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