This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction – Quiz 26 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 26 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is the purpose of using a commutator in an AC generator? A) To convert AC to DC. B) To increase the voltage output. C) To reduce the efficiency of the generator. D) To regulate the frequency of the generated AC. Show Answer Correct Answer: A) To convert AC to DC. 2. AC generator converts: A) Mechanical energy to electrical energy. B) Electrical energy to mechanical energy. C) Heat energy to mechanical energy. D) Chemical energy to electrical energy. Show Answer Correct Answer: A) Mechanical energy to electrical energy. 3. A flat coil of wire consisting of 50 turns, each with an area of 60 cm$^{2}$, is positioned perpendicularly to a uniform magnetic field that increases its magnitude at a constant rate from 3.0 T to 9.0 T in 3.0 s. If the coil has a total resistance of 0.40 $\Omega$, what is the magnitude of the induced current? A) 2.4 A. B) 1.5 A. C) 3.2 A. D) 0.8 A. E) 0.75 A. Show Answer Correct Answer: B) 1.5 A. 4. Observe:While the magnet is not moving, is there any electric field? A) Yes. B) No. C) All the above. D) None of the above. Show Answer Correct Answer: B) No. 5. Observe:Check that Show loop data is on. Move the wire loop up, away from the magnet. Is a current produced in the wire? A) Yes. B) No. C) All the above. D) None of the above. Show Answer Correct Answer: A) Yes. 6. AC generator works on the principle of A) Fleming Right hand rule. B) Fleming Left hand rule. C) Ampere rule. D) Right hand thumb rule. Show Answer Correct Answer: A) Fleming Right hand rule. 7. What is the purpose of an autotransformer? A) To step up the voltage. B) To step down the voltage. C) To isolate the primary and secondary circuits. D) To increase the losses in the transformer. Show Answer Correct Answer: B) To step down the voltage. 8. Faraday's Law states that the magnitude of the induced e.m.f. is ..... to the rate of change of magnetic flux linkage with the solenoid. A) Equal. B) Inversely proportional. C) Directly proportional. D) None of the above. Show Answer Correct Answer: C) Directly proportional. 9. What is motional emf and how is it generated? A) Motional emf is the voltage generated in a conductor moving through a magnetic field. B) Motional emf is the heat generated in a conductor at rest. C) Motional emf is the pressure created in a fluid moving through a conductor. D) Motional emf is the current produced in a stationary magnetic field. Show Answer Correct Answer: A) Motional emf is the voltage generated in a conductor moving through a magnetic field. 10. If the primary power of an ideal transformer having a 2:1 voltage ratio is 100 W, the secondary power is: A) 200 W. B) 75 W. C) 50 W. D) 100 W. Show Answer Correct Answer: D) 100 W. 11. How does electromagnetic induction play a role in the functioning of transformers? A) Electromagnetic induction leads to the production of sound in transformers. B) Electromagnetic induction results in the generation of heat in transformers. C) Electromagnetic induction allows for the transfer of electrical energy between coils in transformers. D) Electromagnetic induction causes mechanical rotation in transformers. Show Answer Correct Answer: C) Electromagnetic induction allows for the transfer of electrical energy between coils in transformers. 12. Write an equation to show that if a transformer is 100% efficient then the power in the secondary coil = power in the primary coil A) Vp x Ip = Vs / Is p.d. across x current in = p.d. across / currentprimary coil primary coil = secondary coil in secondary. B) Vp x Ip = Vs x Is p.d. across x current in = p.d. across x currentprimary coil primary coil = secondary coil in secondary. C) All the above. D) None of the above. Show Answer Correct Answer: B) Vp x Ip = Vs x Is p.d. across x current in = p.d. across x currentprimary coil primary coil = secondary coil in secondary. 13. Lenz's law states that the direction of the induced current is such that it A) Enhances the change in magnetic flux. B) Opposes the change in magnetic flux. C) Follows the direction of the magnetic field. D) Is always in the same direction as the applied current. Show Answer Correct Answer: B) Opposes the change in magnetic flux. 14. Compare:Turn on Show loop data. The current (I) in the loop is measured in amperes. Click Forward and observe both the current and the electric field.How does the current change as the magnet approaches the loop? A) The current increases. B) The current decreases. C) The current remains constant. D) The current fluctuates. Show Answer Correct Answer: A) The current increases. 15. What safety measures are important when working with AC generators? A) Using water to cool the generator. B) Important safety measures include proper grounding, using PPE, maintaining distance from live parts, and following lockout/tagout procedures. C) Working alone without supervision. D) Ignoring electrical codes and standards. Show Answer Correct Answer: B) Important safety measures include proper grounding, using PPE, maintaining distance from live parts, and following lockout/tagout procedures. 16. How does changing the magnetic field affect induced EMF? A) EMF decreases as the magnetic field changes. B) Changing the magnetic field induces EMF proportional to the rate of change. C) Induced EMF is constant regardless of magnetic field changes. D) Changing the magnetic field has no effect on EMF. Show Answer Correct Answer: B) Changing the magnetic field induces EMF proportional to the rate of change. 17. Which of these is NOT a part of a DC Generator. A) Slip rings. B) Commutator. C) Brushes. D) Stator. Show Answer Correct Answer: A) Slip rings. 18. How does electromagnetic induction contribute to wireless charging? A) Wireless charging uses solar panels to generate electricity. B) Electromagnetic induction allows wireless charging by transferring energy through magnetic fields between coils. C) Wireless charging relies on Bluetooth technology for energy transfer. D) Electromagnetic induction is only applicable in wired charging systems. Show Answer Correct Answer: B) Electromagnetic induction allows wireless charging by transferring energy through magnetic fields between coils. 19. A capacitor is connected to a 12V battery and is fully charged. What fraction of the capacitor's voltage decayed after 4 half-lives? A) 1/8. B) 1/16. C) 15/16. D) 1/32. Show Answer Correct Answer: C) 15/16. 20. A device that converts electrical energy into mechanical energy A) Electromagnet. B) Electromagnetic induction. C) Electric motor. D) Electromagnetism. Show Answer Correct Answer: C) Electric motor. 21. The efficiency of the transformer A) X=output power/input power x 100%. B) X=input power/output power x 100%. C) All the above. D) None of the above. Show Answer Correct Answer: A) X=output power/input power x 100%. 22. You wish to generate an EMF of 4.5 V bymoving a wire at 4.0 m/s through a 50 mTmagnetic field. How long must the wire be, and what should be the angle between thefield and direction of motion to use theshortest wire? A) 10 m. B) 50 m. C) 12 m. D) 23 m. Show Answer Correct Answer: D) 23 m. 23. An inductor coil having some resistance is connected to an AC source . which of the following have zero average value over a cycle? A) Induced EMF in the inductor. B) Current. C) Both a and b. D) Neither a nor b. Show Answer Correct Answer: C) Both a and b. 24. Changing magnetic fields can set up current loops in nearby metal bodies. they dissipate electrical energy as heat, such currents are called A) Henry Currents. B) Faraday Currents. C) Eddy currents. D) Inductance current. Show Answer Correct Answer: C) Eddy currents. 25. What is the direction of the induced current according to Lenz's law? A) Same as the change in magnetic flux. B) Opposite to the change in magnetic flux. C) Perpendicular to the change in magnetic flux. D) Random direction. Show Answer Correct Answer: B) Opposite to the change in magnetic flux. ← 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