Q1: 1. Which phenomenon is responsible for the generation of electric current in a coil when there is a change in magnetic field?

• A) Faraday's Law
• B) Lenz's Law
• C) Gauss's Law
• D) Ohm's Law

Q2: 2. A coil of wire is placed near a magnet. If the magnet is moved closer to the coil, what will happen to the induced current in the coil?

• A) Increase
• B) Decrease
• C) Remain constant
• D) Fluctuate

Q3: 3. In a generator, the mechanical energy is converted into

• A) Magnetic energy
• B) Electrical energy
• C) Thermal energy
• D) Kinetic energy

Q4: 4. Which of the following will increase the induced emf in a coil?

• A) Increasing the number of turns in the coil
• B) Reducing the strength of the magnetic field
• C) Decreasing the area of the coil
• D) Keeping the coil stationary

Q5: 5. A changing magnetic field induces an emf in a coil. If the rate of change of magnetic field increases, what happens to the induced emf?

• A) Increases
• B) Decreases
• C) Remains the same
• D) Becomes zero

Q6: 6. Which device uses the principle of electromagnetic induction to measure current in a circuit?

• A) Ammeter
• B) Voltmeter
• C) Galvanometer
• D) Electroscope

Q7: 7. An electric guitar pickup works based on the principle of

• A) Electromagnetic induction
• B) Ohm's Law
• C) Kirchhoff's Law
• D) Coulomb's Law

Q8: 8. Which material is commonly used as the core of an electromagnet to enhance its magnetic field strength?

• A) Copper
• B) Aluminum
• C) Iron
• D) Silver

Q9: 9. Transformers are based on the principle of

• A) Faraday's Law
• B) Lenz's Law
• C) Coulomb's Law
• D) Ohm's Law

Q10: 10. A coil has 100 turns and a magnetic field changes at a rate of 2 T/s. What is the induced emf in the coil?

• A) 200 V
• B) 100 V
• C) 50 V
• D) 20 V

Q11: 11. Which law states that the induced emf in a closed loop is equal to the rate of change of magnetic flux through the loop?

• A) Faraday's Law
• B) Lenz's Law
• C) Ampère's Law
• D) Gauss's Law

Q12: 12. A coil with 50 turns experiences a change in magnetic field at a rate of 0.5 T/s. What is the induced emf if the coil resistance is 10 ohms?

• A) 2.5 V
• B) 5 V
• C) 25 V
• D) 50 V

Q13: 13. Which of the following will decrease the induced emf in a coil?

• A) Increasing the resistance of the coil
• B) Decreasing the speed of the magnet
• C) Increasing the area of the coil
• D) Adding more turns to the coil

Q14: 14. An electric generator in a hydroelectric power plant converts

• A) Mechanical energy to electrical energy
• B) Electrical energy to mechanical energy
• C) Magnetic energy to electrical energy
• D) Heat energy to electrical energy

Q15: 15. A transformer with 200 turns in the primary coil and 400 turns in the secondary coil has a voltage ratio of

• A) 1:1
• B) 1:2
• C) 2:1
• D) 1:4

Q16: 16. Which principle explains why a moving magnet near a coil can generate an electric current?

• A) Ampère's Law
• B) Faraday's Law
• C) Coulomb's Law
• D) Newton's Law

Q17: 17. The direction of the induced current in a coil is determined by

• A) Ampère's Law
• B) Coulomb's Law
• C) Kirchhoff's Law
• D) Lenz's Law

Q18: 18. A coil has an induced emf of 6 V when the magnetic field changes at a rate of 2 T/s. If the coil resistance is 3 ohms, what is the induced current?

• A) 2 A
• B) 3 A
• C) 4 A
• D) 6 A

Q19: 19. Which type of material is best suited for the core of an inductor to minimize energy losses?

• A) Ferromagnetic
• B) Paramagnetic
• C) Non-magnetic
• D) Diamagnetic

Q20: 20. Which device uses the principle of electromagnetic induction to transform voltage levels in power distribution?

• A) Generator
• B) Transformer
• C) Capacitor
• D) Resistor

Q21: 21. A coil with 20 turns has a magnetic field changing at a rate of 0.3 T/s. If the induced emf is 12 V, what is the mutual inductance of the coil?

• A) 0.6 H
• B) 0.4 H
• C) 0.3 H
• D) 0.2 H

Q22: 22. Which factor does not affect the magnitude of the induced emf in a coil?

• A) Strength of the magnetic field
• B) Number of turns in the coil
• C) Speed of the magnet
• D) Length of the wire

Q23: 23. A power plant generates electricity using a turbine that spins a coil in a magnetic field. This process is an example of

• A) Electromagnetic induction
• B) Photoelectric effect
• C) Thermionic emission
• D) Quantum tunneling

Q24: 24. What is the purpose of using a soft iron core in an electromagnet?

• A) To increase resistance
• B) To decrease magnetic field strength
• C) To concentrate magnetic field lines
• D) To insulate the coil

Q25: 25. How does the induced emf in a coil change if the coil is rotated at a faster rate in a magnetic field?

• A) Increases
• B) Decreases
• C) Remains the same
• D) Becomes zero