Chapter4 Electromagnetism

The motion of a current carrying conductor in a magnetic field can be determined by

• Direction of current flow

• Fleming’s Right Hand Rule

• Fleming’s Left Hand Rule

• Right Hand Grip Rule

Diagram below shows an electric motor.

Which magnetic field pattern is correct when the switch is closed?

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Diagram below shows a current carrying coil in a magnetic field.

Which of the following will not affect the speed of rotation of the coil?

• The current flowing in the coil

• The number of turns of wire in the coil

• The direction of the current flowing in the coil

• The strength of magnetic field

Diagram below shows a current-carrying conductor in magnetic field.

What is the direction of the force that acts on the conductor?

• A

• B

• C

• D

Diagram shows an experimental set up where a bar magnet is placed near a solenoid which is connected to a galvanometer.

Which of the following actions will not produce deflection of the galvanometer?

• moving the magnet towards the solenoid

• moving the solenoid towards the magnet

• both the magnet and solenoid are moved with the same velocity

• both the magnet and solenoid are moved towards each other

Diagram shows a bar magnet is moving towards a solenoid.

What is the magnetic polarity at both ends of the solenoid, X and Y?

• X - South Y - South

• X - South Y - North

• X - North Y - North

• X - North Y - South

A straight conductor is moved perpendicularly to the magnetic field.

Which of the following diagrams shows the correct direction of the induced current in the conductor?

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Diagram shows an ideal transformer. If the 60 W bulb is lit to its normal brightness, what is the value of the input current I_p?

• 0.025 A

• 0.1 A

• 0.25 A

• 2.5 A

Diagram shows a transformer that is used to light up a bulb.

Which of the following statements is true about the transformer?

• Type of transformer / Voltage across the bulb

  Step-up / 480 V

• Type of transformer / Voltage across the bulb

  Step-up / 960 V

• Type of transformer / Voltage across the bulb

  Step-down / 41.7 V

• Type of transformer / Voltage across the bulb

  Step-down / 60 V

The function of the transformer in the transmission of electricity is to

• change the voltage magnitude

• increase the power

• increase the resistance

• reduce the time to transmit the electricity