Electromagnet Form 5 KSSM

Diagram shows a right hand which represents the Fleming Right Hand Rule . X represent the

• Current

• Motion

• Magnetic Field

• Potential DIfference

Diagram 25 shows the setup of the apparatus to study the pattern of he magnetic field produced by the current in a straight wire

Which diagram shows the correct pattern direction of the magnetic field observed by the observer?

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Diagram shows a bar magnet is moving towards a solenoid

What is the magnetic pole 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

Diagram shows a transformer that has efficiency 80%

If it produces an output power of 100 W, what is the amount of current flowing in the primary coil?

• 6.25 A

• 5.15 A

• 4.00 A

• 3.75 A

Diagram shows an electric motor

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

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Diagram below shows a wire QR hangs freely between two strong magnets

The angle of deflection is increased by

• increasing the current

• changing the polarity of magnet

• increasing the resistance of wire QR

• increasing the distance between the poles of the magnet

Diagram below shows an electric generator

Which graph shows the correct output between voltage and time when the coil starts to rotate?

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Diagram shows the primary coil of a transformer is connected to a 240 V a.c supply and an output voltage of 12 V is produced

What is the ratio of number of turns in the secondary coil , Ns to the number of turns in the primary coil, Np ?

• 40 : 2

• 4 : 24

• 1 : 20

• 2 : 40

Diagram shows a pattern of magnetic field produced by a current-carrying conductor

Which of the following will decrease the distance between the magnetic field lines?

• Inverse the terminal of dry cell

• Increase the number of dry cell

• Decrease the thickness of connecting wire

• Replace 1.5 V d.c dry cell with 1.5 V a.c power supply

The speed of direct current motor can be reduced by

• increasing the amount of current

• increasing the strength of magnet

• increasing the number of turns of coil

• increasing the resistance of coil wire