This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction – Quiz 24 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 24 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Which description best applies to Lenz's Law? A) An induced current occurs when a magnet passes through a tube. B) When a change in magnetic field occurs to a coil the direction of current goes in the in the other direction to this change. C) The direction of an induced current is such to align with the change that created it. D) A magnet is a tube is always slowed by its magnetic field. Show Answer Correct Answer: B) When a change in magnetic field occurs to a coil the direction of current goes in the in the other direction to this change. 2. If there's a wire that contains electric current and facing the paper, in which direction the magnetic field it will produce? A) Clockwise. B) Counter-clockwise. C) Facing the paper also. D) Towards the reader. Show Answer Correct Answer: A) Clockwise. 3. Write the condition under which an electron will move and reflected in the presence of crossed electric and magnetic field A) V=E/B. B) V=B/E. C) V=EB. D) V=E. Show Answer Correct Answer: A) V=E/B. 4. How can eddy currents be minimized in electrical devices? A) Increase the size of the core. B) Lower frequency DC. C) Use solid metal cores. D) Use laminated cores, high-resistance materials, thinner sections, and higher frequency AC. Show Answer Correct Answer: D) Use laminated cores, high-resistance materials, thinner sections, and higher frequency AC. 5. In a step-down transformer: A) Both current and voltage decrease. B) Both current and voltage increase. C) Voltage decreases, current increases. D) Voltage increases, current decreases. Show Answer Correct Answer: C) Voltage decreases, current increases. 6. Generators use induction to produce electricity. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 7. Which of the following is most suitable for the core of electromagnets A) Soft iron. B) Soft iron. C) SteelCopper-nickel alloy. D) Air. Show Answer Correct Answer: A) Soft iron. 8. The S.I. unit of magnetic flux is A) Tesla. B) Weber. C) Joule. D) Newton. Show Answer Correct Answer: B) Weber. 9. In the context of electricity, what is resistance? A) How difficult electrons are to flow in a substance. B) How difficult it is to generate voltage from current. C) The ratio between voltage applied and current generated. D) All of these. Show Answer Correct Answer: D) All of these. 10. Is the unit for self-induction and mutual induction the same? A) Yes. B) No. C) All the above. D) None of the above. Show Answer Correct Answer: A) Yes. 11. A long solenoid has self inductance L. If its length is doubled keeping total number of turns constant then itsnew self inductance will be A) L. B) L/2. C) 2L. D) L/4. Show Answer Correct Answer: B) L/2. 12. Question 3 A) A. B) B. C) C. D) D. Show Answer Correct Answer: A) A. 13. If the magnetic field through a coil is increased, what happens to the induced emf? A) It increases. B) It becomes zero. C) It decreases. D) It remains constant. Show Answer Correct Answer: A) It increases. 14. A generator uses electromagnetic induction to produce electricity. What is the main component of a generator? A) A battery. B) A magnet. C) A light bulb. D) None of the above. Show Answer Correct Answer: B) A magnet. 15. A coil of 2 turns is placed in a magnetic field which changes from 4 Wb/m2 to 8 Wb/m 2 in 2 seconds. Find the induced e.m.f. in the coil A) -4 V. B) -5 V. C) -6 V. D) -7 V. Show Answer Correct Answer: A) -4 V. 16. The direction of induced current in the coil can be reversed by A) Reversing the direction of the battery. B) Reversing the magnetic field. C) Keeping the magnet stationery in the coil. D) Connecting an ammeter in the circuit. Show Answer Correct Answer: B) Reversing the magnetic field. 17. The magnetic field of an electromagnet ..... A) Can be turned on and off. B) Is permanent. C) Lasts for only one hour. D) Lasts for one day. Show Answer Correct Answer: A) Can be turned on and off. 18. The turn ratio (r) for a step-up transformer is A) R = 0. B) R > 1. C) R < 1. D) R = 1. Show Answer Correct Answer: B) R > 1. 19. Which of the following is NOT an application of Lenz's Law A) Transformers. B) AC generator. C) A coil traversed by AC current. D) A DC motor. Show Answer Correct Answer: D) A DC motor. 20. Experiment:Drag the loop to the left edge, and then slowly move the loop horizontally to the right edge. Observe the flux as you do this. Is a current produced in the wire? A) Yes, a current is produced. B) No, a current is not produced. C) All the above. D) None of the above. Show Answer Correct Answer: A) Yes, a current is produced. 21. How does the concept of induction apply to wireless charging? A) Wireless charging relies solely on infrared radiation for energy transfer. B) Induction in wireless charging requires physical contact between devices. C) Induction uses direct current to charge devices wirelessly. D) Induction in wireless charging involves generating a magnetic field through an alternating current, which induces a current in a nearby coil for energy transfer. Show Answer Correct Answer: D) Induction in wireless charging involves generating a magnetic field through an alternating current, which induces a current in a nearby coil for energy transfer. 22. At what speed would a 20 cm length ofwire have to move across a 2.5 T magneticfield to induce an EMF of 10 V? A) 20 m/s. B) 10 m/s. C) 5 m/s. D) 2.5 m/s. Show Answer Correct Answer: A) 20 m/s. 23. Who first demonstrated that electric currents can be induced by changing magnetic fields? A) Ampere. B) Oersted. C) Joseph Henry. D) Michael Faraday. Show Answer Correct Answer: D) Michael Faraday. 24. The RMS value of the current is related to the peak value A) 0.708 Io. B) 0.707 Io. C) 0.710 Io. D) None. Show Answer Correct Answer: B) 0.707 Io. 25. A device that converts mechanical energy into electrical energy is called ..... A) Motor. B) Generator. C) Transformer. D) Robot. Show Answer Correct Answer: B) Generator. ← 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