ELECTROMAGNETISM

If the strength of current flowing through a wire is increased, what happens to the strength of the magnetic field produced by it?

• Remains unchanged

• Increases

• Decreases

• First increases and then decreases

Which of the following will decrease the strength of a magnetic field due to current through a circular loop?

• Increasing the number of turns in the coil

• Increasing the strength of the current flowing through the coil

• Increasing the radius of the coil

• None of these

If the resistance of the rheostat attached in the circuit providing current to a wire is increased, what will happen to its magnetic field strength?

• Remain the same

• Increase

• Decrease

• Cannot be decided based on this parameter alone

A permanent magnet is made of which material?

• Soft iron

• Nickel

• Steel

• Copper

Which rule helps to find the direction of force acting on a current-carrying conductor?

• Lenz's law

• Right-hand thumb rule

• Fleming's right-hand rule

• Fleming's left-hand rule

What does a coil carrying current experience when placed between the pole pieces of a magnet?

• Pressure

• Couple

• Electrical force

• None of these

What is the energy conversion in a DC motor?

• Magnetic to electrical

• Mechanical to electrical

• Electrical to magnetic

• Electrical to mechanical

Which rule gives the direction of induced current in a conductor?

• Fleming's left-hand rule

• Fleming's right-hand rule

• Right-hand thumb rule

• Lenz's law

What is the energy conversion taking place in an AC generator?

• Mechanical to electrical

• Electrical to mechanical

• Magnetic to electrical

• Electrical to magnetic

The frequency of AC current supplied to our houses is 50 Hz. How many times does the polarity of the current change in 1 second?

• 25

• 50

• 100

• None of the above