This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction – Quiz 31 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 31 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. A loop of area 0.45 m$^{2}$ is in a uniform 0.03 T magnetic field. If the flux through the loop is 1.1 x 10$^{-2}$ Wb, what angle does the plane of the loop make with the magnetic field? A) 25 degrees. B) 35 degrees. C) 65 degrees. D) 55 degrees. E) 90 degrees. Show Answer Correct Answer: D) 55 degrees. 2. What is the cause of induced electric current in a secondary coil? A) Change in voltage. B) Change in temperature. C) Change in resistance. D) Change in magnetic field lines. Show Answer Correct Answer: D) Change in magnetic field lines. 3. Lenz's law obey ..... A) Second's newton law of motion. B) Principle of conservation of energy. C) Total conservation of momentum. D) None of the above. Show Answer Correct Answer: B) Principle of conservation of energy. 4. What happens when a wire cuts through magnetic field lines? A) It breaks. B) It becomes magnetic. C) It generates heat. D) A voltage is induced. Show Answer Correct Answer: D) A voltage is induced. 5. The voltage across the input terminals of a transformer is 110 V. The primary coil has 50 turns and the secondary coil has 120 turns. The output voltage of the transformer is A) 46 V. B) 55 V. C) 180 V. D) 264 V. Show Answer Correct Answer: D) 264 V. 6. Transformer works on which of the following principle A) Lenz's Law. B) Ampere's Law. C) Faraday's Law of Electromagenetic Induction. D) Fleming's Law. Show Answer Correct Answer: C) Faraday's Law of Electromagenetic Induction. 7. According to Lenz's law the direction of an induced current in a conductor will be that which tends to produce which of the following effects? A) Enhance the effect which produces it. B) Produce a greater heating effect. C) Produce the greatest voltage. D) Oppose the effect which produces it. Show Answer Correct Answer: D) Oppose the effect which produces it. 8. What happens when you move a bar magnet in and out of a coil of copper wire? A) Electric current would be produced in the magnet. B) The magnet would do nothing to the coil of wire. C) Electric current would be produced in the copper wire. D) It would make the copper wire produce a magnetic field. Show Answer Correct Answer: C) Electric current would be produced in the copper wire. 9. What happens if the wire remains still and the magnets move instead? A) A potential difference is still induced. B) No potential difference is induced. C) The magnetic field collapses. D) The potential difference decreases. Show Answer Correct Answer: A) A potential difference is still induced. 10. What is the effect of moving a magnet quickly in and out of a coil? A) It decreases the rate of change of magnetic flux, resulting in a lower induced voltage. B) It increases the rate of change of magnetic flux, resulting in a higher induced voltage. C) It has no effect on the magnetic flux or induced voltage. D) It reverses the direction of the magnetic field in the coil. Show Answer Correct Answer: B) It increases the rate of change of magnetic flux, resulting in a higher induced voltage. 11. In a transformer, the input power is ..... the output power. A) Less than. B) Equal to. C) Greater than. D) None of the above. Show Answer Correct Answer: B) Equal to. 12. Faraday's law relates to which of the following? A) Electric current and flux. B) Magnetic field and current. C) Voltage, current, and flux. D) Voltage and magnetic flux. E) None of these. Show Answer Correct Answer: D) Voltage and magnetic flux. 13. In which direction does the induced current flow in a circuit according to Lenz's Law? A) Opposite direction of the change in magnetic field. B) Same direction of the change in magnetic field. C) Random direction. D) No direction. Show Answer Correct Answer: A) Opposite direction of the change in magnetic field. 14. Which of the following gives the direction of the induced e.m.f.? A) Faraday's law. B) Lenz's law. C) Ampere. D) Biot-Savart's law. Show Answer Correct Answer: B) Lenz's law. 15. A transformer is used to step up and alternating EMF of 200 volt to 440 volt.if the primary coil has 1000 turns.calculate the number of turns in the secondary coil A) 2230. B) 2232. C) 2200. D) 2220. Show Answer Correct Answer: C) 2200. 16. What is the purpose of the earth wire in a domestic circuit? A) To regulate current flow. B) To increase resistance. C) To prevent short-circuiting. D) To provide insulation. Show Answer Correct Answer: C) To prevent short-circuiting. 17. Magnetic flux o(in Weber) linked with a closed circuit of resistance 10 ohm varies with time t(in seconds) as = 5t-4t + 1. The induced emf in the circuit at t = 0.2 sec. is A) 0.4 V. B) -0.4 V. C) -2.0 V. D) 2.0 V. Show Answer Correct Answer: D) 2.0 V. 18. To attract means ..... A) The part of the magnet where the force is the strongest. B) A force created by magnets that pulls some metals. C) To Pull towards. D) An object able to pull some metals towards itself. Show Answer Correct Answer: C) To Pull towards. 19. Magnetic flux is defined as A) The product of magnetic field strength and area. B) The scalar product of magnetic flux density and the area vector. C) The vector product of magnetic field and area. D) The product of magnetic field and current. Show Answer Correct Answer: B) The scalar product of magnetic flux density and the area vector. 20. A magnet is moved towards a coil (i) quickly (ii) slowly. The induced potential difference A) More in (i) than in (ii) case. B) More in (ii) than in (i) case. C) Same in both. D) Can't say. Show Answer Correct Answer: A) More in (i) than in (ii) case. 21. A device that converts mechanical energy into electrical energy A) Electric generator. B) Electric motor. C) Electromagnetic induction. D) Mechanical generator. Show Answer Correct Answer: A) Electric generator. 22. Which of the following scientists discovered that a changing magnetic field is required to induce an electric current? A) Einstein. B) Lenz. C) Maxwell. D) Faraday. Show Answer Correct Answer: D) Faraday. 23. If velocity of a conductor moving through a magnetic field B is made zero, then motional emf is: A) $-Blv$. B) $-\frac{v}{Bl}$. C) Zero. D) $-\frac{Bl}{v}$. Show Answer Correct Answer: C) Zero. 24. Which of the following sentences is not true? A) Motors convert electrical energy to mechanical energy. B) Generators convert mechanical energy to electric energy. C) A generator is connected to a battery. D) A generator uses slip rings while the motor uses split rings. E) Both motors and generators have brushes. Show Answer Correct Answer: C) A generator is connected to a battery. 25. Below are the factors affecting the magnitude of induced e.m.f except ..... A) Increases the speed of relative motion. B) Increases the number of turns of the solenoid. C) Decreases the strength of magnetic field. D) None of the above. Show Answer Correct Answer: C) Decreases the strength of magnetic field. ← 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