This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction – Quiz 23 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 23 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is the use of slip rings in a simple a.c. generator? A) To increase the rotational speed of the coil. B) To prevent the wire from entanglement. C) To change the direction of current flowing to the load in every half a turn. D) To ensure good contacts between the moving parts and the stationary parts. Show Answer Correct Answer: D) To ensure good contacts between the moving parts and the stationary parts. 2. What happens to the induced current if the speed of the moving magnet is increased? A) The current decreases. B) The current increases. C) The current remains the same. D) The current reverses direction. Show Answer Correct Answer: B) The current increases. 3. The direction of a magnetic field's lines always head towards the South pole. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 4. Derive an expression for the motional EMF induced across the ends of a conducting rod moving in a uniform perpendicular magnetic field A) E=Blv. B) E=Blq. C) E=Blx. D) E=Bla. Show Answer Correct Answer: A) E=Blv. 5. A solenoid bent in the form of a closed ring is called ..... A) Cyclotron. B) Solenoid. C) Toroidal solenoid. D) None. Show Answer Correct Answer: C) Toroidal solenoid. 6. What is inside a toy car that turns the wheels? A) Generator. B) Electric motor. C) Electromagnet. D) None of the above. Show Answer Correct Answer: B) Electric motor. 7. A resistor of resistance 100 ohms is connected in series with a 10mF capacitor. What is its half-life? A) 0.693s. B) 6.93s. C) 693s. D) 10s. Show Answer Correct Answer: A) 0.693s. 8. What is the role of a coil in an AC generator? A) The coil converts direct current into mechanical energy. B) The coil stores electrical energy for later use. C) The coil acts as a transformer to increase voltage. D) The coil generates alternating current by rotating in a magnetic field, inducing electromotive force. Show Answer Correct Answer: D) The coil generates alternating current by rotating in a magnetic field, inducing electromotive force. 9. Insulators are put between core lamination ..... A) To prevent flux leaks to the neighboring steel sheet. B) To reduce the cross-sectional area of the core. C) To prevent short circuit in the transformer. D) To prevent rusting in the lamination. Show Answer Correct Answer: C) To prevent short circuit in the transformer. 10. Number of magnetic field line passes through an area is the definition for A) Magnetic flux. B) Current carrying conductors. C) Induced emf. D) Magnetic field. Show Answer Correct Answer: A) Magnetic flux. 11. How is contact between the coil and circuit maintained in an AC generator? A) A split ring commutator connects to each side for half a turn. B) It cannot be maintained. C) The alternator can only complete one revolution and must then be rotated in reverse. D) Slip rings and brushes allow continuous connection. Show Answer Correct Answer: D) Slip rings and brushes allow continuous connection. 12. Explain Lenz's law. A) The direction of an induced current in a conductor opposes the change that produced it. B) The direction of an induced current in a conductor is the same as the change that produced it. C) Lenz's law states that there is no induced current in a conductor. D) Lenz's law only applies to magnetic fields. Show Answer Correct Answer: A) The direction of an induced current in a conductor opposes the change that produced it. 13. The Fleming's right-hand rule is used when ..... A) Motion causes current. B) Current causes motion. C) Current causes potential difference. D) Motion causes magnetic field. Show Answer Correct Answer: A) Motion causes current. 14. What factors affect the magnitude of induced electromotive force (emf) in a conductor? A) Type of material of the conductor. B) Temperature of the conductor. C) Rate of change of magnetic field, length of the conductor, and strength of the magnetic field. D) Color of the conductor. Show Answer Correct Answer: C) Rate of change of magnetic field, length of the conductor, and strength of the magnetic field. 15. Explain how transformers utilize electromagnetic induction. A) Transformers utilize electromagnetic induction by transferring energy from one coil to another through a changing magnetic field generated by alternating current. B) Transformers generate electricity through static electricity. C) Transformers convert mechanical energy into electrical energy directly. D) Transformers operate solely on direct current without any magnetic field. Show Answer Correct Answer: A) Transformers utilize electromagnetic induction by transferring energy from one coil to another through a changing magnetic field generated by alternating current. 16. A solenoid have the self inductance 2H. If length of the solenoid is doubled having turn density and area constant then new self inductance is: A) 4H. B) 1H. C) 8H. D) 0.5 H. Show Answer Correct Answer: C) 8H. 17. Increasing the speed of the magnet affects the strength of the electric field. How does it affect? A) It increases the strength of the electric field. B) It decreases the strength of the electric field. C) It has no effect on the strength of the electric field. D) It reverses the direction of the electric field. Show Answer Correct Answer: A) It increases the strength of the electric field. 18. The self-inductance of a coil depends on A) The current flowing through the coil. B) The number of turns, area, and permeability of the medium. C) The resistance of the coil. D) The applied voltage. Show Answer Correct Answer: B) The number of turns, area, and permeability of the medium. 19. What role does the magnetic field play in electromagnetic induction? A) The magnetic field only affects stationary charges. B) The magnetic field does not influence electrical circuits. C) The magnetic field induces electromotive force (EMF) in a conductor when it changes. D) The magnetic field generates heat in conductors. Show Answer Correct Answer: C) The magnetic field induces electromotive force (EMF) in a conductor when it changes. 20. Fleming's left-hand rule should be used if one were to create motion, while Fleming's right-hand rule should be used if one were to create electricity. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 21. What is the function of an electric fuse in a domestic circuit? A) To control resistance. B) To regulate voltage. C) To prevent overloading. D) To increase current flow. Show Answer Correct Answer: C) To prevent overloading. 22. What is the unit of induced voltage? A) Ampere (A). B) Ohm ($\Omega$). C) Volt (V). D) Watt (W). Show Answer Correct Answer: C) Volt (V). 23. The emf induced in a coil of wire is proportional to what? A) The strength of the magnetic field. B) The rate of change of the magnetic flux through the coil. C) The resistance of the wire. D) None of the above. Show Answer Correct Answer: B) The rate of change of the magnetic flux through the coil. 24. How can you maximize the voltage from a generator? A) Increase the magnetic field strength. B) Increase the change in the magnetic field. C) Increase the internal resistance. D) Align the coil parallel to the magnetic fields. Show Answer Correct Answer: B) Increase the change in the magnetic field. 25. What is electric generator? A) An electric generator is a device that converts mechanical energy into electrical energy. B) A machine that converts electrical energy into mechanical energy. C) A tool used for measuring electrical current. D) A device that stores electrical energy for later use. Show Answer Correct Answer: A) An electric generator is a device that converts mechanical energy into electrical energy. ← PreviousNext →Related QuizzesClass 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 1Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 2Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 3Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 4Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 5Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 6Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 7Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 8Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 9Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 10 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books