Electromagnetic Concepts Unveiled: Self-Inductance and Mutual Inductance Essentials for HTET 2023

Welcome, HTET 2023 aspirants, to a specialized guide designed to help you conquer the intricacies of self-inductance and mutual inductance through multiple-choice questions (MCQs). These electromagnetic phenomena form a critical part of the physics syllabus for the Haryana Teacher Eligibility Test (HTET) and mastering them is essential for scoring well. In this blog post, we will not only demystify the concepts but also provide you with valuable insights and strategies to tackle MCQs effectively. So, let's dive into the world of self-inductance and mutual inductance and equip ourselves for success in the upcoming HTET examination.

1.     What is self-inductance? 

A)   The tendency of a coil to oppose a change in current flowing through it. 

B)   The ability of a coil to induce a voltage in another nearby coil. 

C)   The resistance of a coil to the flow of direct current. 

D)   The phenomenon where two coils mutually induce voltages in each other. 

2.     Which unit is used to measure self-inductance? 

A)   Ohm (Ω) 

B)   Volt (V) 

C)   Henry (H) 

D)   Farad (F) 

3.     If the current in a coil with self-inductance of 2 Henry changes at a rate of 4 Amperes per second, what is the induced voltage? 

A)   0.5 V 

B)   2 V 

C)   4 V 

D)   8 V 

4.     When the current in a coil increases, what happens to the magnetic field and self-inductance? 

A)   Magnetic field decreases, self-inductance decreases. 

B)   Magnetic field increases, self-inductance decreases. 

C)   Magnetic field decreases, self-inductance increases. 

D)   Magnetic field increases, self-inductance increases. 

5.     What is mutual inductance? 

A)   The ability of a coil to induce a voltage in itself. 

B)   The tendency of a coil to oppose a change in current in another nearby coil. 

C)   The resistance of a coil to the flow of alternating current. 

D)   The phenomenon where two coils induce voltages in each other. 

6.     Which unit is used to measure mutual inductance? 

A)   Ohm (Ω) 

B)   Volt (V) 

C)   Henry (H) 

D)   Farad (F) 

7.     If the mutual inductance between two coils is 3 Henry and the rate of change of current in one coil is 2 Amperes per second, what is the induced voltage in the other coil? 

A)   1 V 

B)   2 V 

C)   3 V 

D)   6 V 

8.     In a transformer, which coil has more turns of wire, the primary or the secondary coil, to achieve step-up voltage transformation? 

A)   Primary coil 

B)   Secondary coil 

C)   Both have the same number of turns 

D)   It depends on the transformer design 

9.     When two coils have a strong mutual inductance, what happens to the efficiency of energy transfer between them? 

A)   Efficiency increases 

B)   Efficiency decreases 

C)   Efficiency remains unchanged 

D)   Efficiency depends on the voltage 

10. Mutual inductance is a key principle used in the operation of: 

A)   Batteries 

B)   Resistors 

C)   Capacitors 

D)   Transformers

11. Which of the following factors affects the self-inductance of a coil? 

A)   The resistance of the coil 

B)   The number of turns of wire in the coil 

C)   The material from which the coil is made 

D)   The length of the coil 

12. According to Lenz's Law, the direction of the induced voltage in a coil due to self-inductance will be: 

A)   In the same direction as the change in current 

B)   In the opposite direction to the change in current 

C)   Independent of the change in current 

D)   Perpendicular to the coil 

13. If the self-inductance of a coil is doubled, and the current flowing through it remains constant, what happens to the induced voltage? 

A)   It doubles 

B)   It halves 

C)   It remains the same 

D)   It becomes zero 

14. What is the formula for calculating the self-induced voltage (emf) in a coil? 

A)   emf = L / (di/dt) 

B)   emf = L * (di/dt) 

C)   emf = (di/dt) / L 

D)   emf = (di/dt) * L

15. In mutual inductance, when the current in the primary coil changes, what happens in the secondary coil? 

A)   No induced voltage is generated in the secondary coil 

B)   An induced voltage is generated in the secondary coil 

C)   The secondary coil opposes the change in current 

D)   The secondary coil remains unaffected 

16. In a transformer, if the primary coil has 200 turns and the secondary coil has 400 turns, what is the turns ratio? 

A)   1:1 

B)   2:1 

C)   1:2 

D)   1:4 

17. Mutual inductance is dependent on which of the following factors? 

A)   The resistance of the coils 

B)   The number of turns in the primary coil 

C)   The magnetic permeability of the material between the coils 

D)   The length of the coils 

18. When the mutual inductance between two coils is high, what does this indicate about their magnetic coupling? 

A)   They are loosely coupled 

B)   They are tightly coupled 

C)   The coils have the same number of turns 

D)   Mutual inductance is not related to magnetic coupling 

19. In a step-down transformer, compared to the primary coil, the secondary coil typically has: 

A)   More turns 

B)   Fewer turns 

C)   The same number of turns 

D)   A different material 

20. What is the main application of mutual inductance in electrical circuits? 

A)   Generating electricity from solar panels 

B)   Wireless power transmission 

C)   Capacitor charging 

D)   Producing magnetic fields in solenoids

21. Which of the following factors affects the self-inductance of a coil? 

A)   The resistance of the coil 

B)   The cross-sectional area of the coil 

C)   The material inside the coil 

D)   The temperature of the surroundings 

22. What is the unit of self-inductance? 

A)   Volt (V) 

B)   Henry (H) 

C)   Ohm (Ω) 

D)   Tesla (T) 

23. When the current in a coil decreases, what happens to the induced voltage due to self-inductance? 

A)   It increases 

B)   It decreases 

C)   It remains constant 

D)   It depends on the number of turns in the coil 

24. In a coil with self-inductance, what is the energy stored in the magnetic field proportional to? 

A)   The square of the current in the coil 

B)   The square of the number of turns in the coil 

C)   The resistance of the coil 

D)   The cross-sectional area of the coil

25. In mutual inductance, what happens to the induced voltage in the secondary coil when the magnetic coupling between the coils is increased? 

A)   The induced voltage decreases 

B)   The induced voltage remains the same 

C)   The induced voltage increases 

D)   The induced voltage becomes zero 

26. Mutual inductance between two coils can be increased by: 

A)   Increasing the distance between the coils 

B)   Decreasing the number of turns in the primary coil 

C)   Increasing the number of turns in the secondary coil 

D)   Using a non-magnetic material between the coils 

27. Which component in a transformer is responsible for transferring electrical energy from the primary coil to the secondary coil? 

A)   Iron core 

B)   Capacitor 

C)   Resistor 

D)   Diode 

28. In a step-up transformer, if the primary coil has 100 turns and the secondary coil has 500 turns, what is the turns ratio? 

A)   1:5 

B)   5:1 

C)   1:2 

D)   2:1 

29. What is the primary application of mutual inductance in electrical engineering? 

A)   Charging capacitors 

B)   Generating magnetic fields 

C)   Voltage regulation in transformers 

D)   Reducing resistance in wires 

As you prepare for the HTET 2023 examination, remember that self-inductance and mutual inductance are pivotal topics that require a strong foundation. By practicing the MCQs provided in this guide and understanding the underlying concepts, you are on your way to mastering these aspects of electromagnetic induction. Stay dedicated to your studies, seek clarification whenever needed, and keep practicing until you're confident in your abilities. The HTET is your gateway to a rewarding career in teaching, and with the knowledge you've gained here, you're well on your way to achieving success. Best of luck!