This quiz works best with JavaScript enabled. Home > Cbse > Class 12 > Science > Physics Part I > Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction – Quiz 10 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 10 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is the role of a coil in an AC generator? A) The coil acts as a transformer to increase voltage. B) The coil converts direct current into mechanical energy. C) The coil generates alternating current by rotating in a magnetic field, inducing electromotive force. D) The coil stores electrical energy for later use. Show Answer Correct Answer: C) The coil generates alternating current by rotating in a magnetic field, inducing electromotive force. 2. Insulators are put between core lamination ..... A) To prevent flux leaks to the neighboring steel sheet. B) To prevent short circuit in the transformer. C) To reduce the cross-sectional area of the core. D) To prevent rusting in the lamination. Show Answer Correct Answer: B) To prevent short circuit in the transformer. 3. Number of magnetic field line passes through an area is the definition for A) Induced emf. B) Magnetic flux. C) Magnetic field. D) Current carrying conductors. Show Answer Correct Answer: B) Magnetic flux. 4. 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. 5. Explain Lenz's law. A) Lenz's law states that there is no induced current in a conductor. B) The direction of an induced current in a conductor opposes the change that produced it. C) The direction of an induced current in a conductor is the same as the change that produced it. D) Lenz's law only applies to magnetic fields. Show Answer Correct Answer: B) The direction of an induced current in a conductor opposes the change that produced it. 6. The Fleming's right-hand rule is used when ..... A) Current causes potential difference. B) Current causes motion. C) Motion causes magnetic field. D) Motion causes current. Show Answer Correct Answer: D) Motion causes current. 7. 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. 8. Explain how transformers utilize electromagnetic induction. A) Transformers generate electricity through static electricity. B) Transformers operate solely on direct current without any magnetic field. C) Transformers utilize electromagnetic induction by transferring energy from one coil to another through a changing magnetic field generated by alternating current. D) Transformers convert mechanical energy into electrical energy directly. Show Answer Correct Answer: C) Transformers utilize electromagnetic induction by transferring energy from one coil to another through a changing magnetic field generated by alternating current. 9. 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) 0.5 H. C) 1H. D) 8H. Show Answer Correct Answer: D) 8H. 10. Increasing the speed of the magnet affects the strength of the electric field. How does it affect? A) It decreases the strength of the electric field. B) It increases 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: B) It increases the strength of the electric field. 11. 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. 12. 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. 13. What is the function of an electric fuse in a domestic circuit? A) To prevent overloading. B) To increase current flow. C) To control resistance. D) To regulate voltage. Show Answer Correct Answer: A) To prevent overloading. 14. What is the unit of induced voltage? A) Ohm ($\Omega$). B) Volt (V). C) Ampere (A). D) Watt (W). Show Answer Correct Answer: B) Volt (V). 15. 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. 16. 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. 17. What is electric generator? A) A tool used for measuring electrical current. B) An electric generator is a device that converts mechanical energy into electrical energy. C) A machine that converts electrical energy into mechanical energy. D) A device that stores electrical energy for later use. Show Answer Correct Answer: B) An electric generator is a device that converts mechanical energy into electrical energy. 18. Which description best applies to Lenz's Law? A) A magnet is a tube is always slowed by its magnetic field. 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) An induced current occurs when a magnet passes through a tube. 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. 19. If there's a wire that contains electric current and facing the paper, in which direction the magnetic field it will produce? A) Towards the reader. B) Counter-clockwise. C) Clockwise. D) Facing the paper also. Show Answer Correct Answer: C) Clockwise. 20. Write the condition under which an electron will move and reflected in the presence of crossed electric and magnetic field A) V=B/E. B) V=E. C) V=EB. D) V=E/B. Show Answer Correct Answer: D) V=E/B. 21. 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. 22. 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. 23. 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. 24. 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. 25. The S.I. unit of magnetic flux is A) Newton. B) Joule. C) Weber. D) Tesla. Show Answer Correct Answer: C) Weber. 26. 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. 27. 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. 28. 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/4. B) L/2. C) 2L. D) L. Show Answer Correct Answer: B) L/2. 29. If the magnetic field through a coil is increased, what happens to the induced emf? A) It increases. B) It decreases. C) It becomes zero. D) It remains constant. Show Answer Correct Answer: A) It increases. 30. 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. 31. 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) -5 V. B) -6 V. C) -7 V. D) -4 V. Show Answer Correct Answer: D) -4 V. 32. The direction of induced current in the coil can be reversed by A) Reversing the magnetic field. B) Reversing the direction of the battery. C) Connecting an ammeter in the circuit. D) Keeping the magnet stationery in the coil. Show Answer Correct Answer: A) Reversing the magnetic field. 33. 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. 34. Which of the following is NOT an application of Lenz's Law A) Transformers. B) A coil traversed by AC current. C) AC generator. D) A DC motor. Show Answer Correct Answer: D) A DC motor. 35. 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. 36. 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 involves generating a magnetic field through an alternating current, which induces a current in a nearby coil for energy transfer. C) Induction in wireless charging requires physical contact between devices. D) Induction uses direct current to charge devices wirelessly. Show Answer Correct Answer: B) Induction in wireless charging involves generating a magnetic field through an alternating current, which induces a current in a nearby coil for energy transfer. 37. 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) 5 m/s. C) 10 m/s. D) 2.5 m/s. Show Answer Correct Answer: A) 20 m/s. 38. Who first demonstrated that electric currents can be induced by changing magnetic fields? A) Ampere. B) Michael Faraday. C) Joseph Henry. D) Oersted. Show Answer Correct Answer: B) Michael Faraday. 39. 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. 40. A device that converts mechanical energy into electrical energy is called ..... A) Transformer. B) Robot. C) Motor. D) Generator. Show Answer Correct Answer: D) Generator. 41. In a closed conductive circuit contained in an alternating magnetic field, an induction current arises, the magnetic field of which is directed ..... A) Just like an external magnetic field;. B) Perpendicular to the outer field;. C) So as to counteract changes in the external magnetic field. D) Opposite to the outer field;. Show Answer Correct Answer: C) So as to counteract changes in the external magnetic field. 42. Which of the following explains Electromagnetic Induction? A) Emf is induced when there is a change in electric flux through a conductor. B) Current is induced when the voltage changes through a conductor. C) Emf is induced when there is a change in magnetic flux through a conductor. D) Voltage is induced when the current changes through a conductor. Show Answer Correct Answer: C) Emf is induced when there is a change in magnetic flux through a conductor. 43. What is/are the factor/s involved in Faraday's Law? A) Time. B) Flux. C) Number loops. D) All of the choices. Show Answer Correct Answer: D) All of the choices. 44. For an experiment, Mohammed assembled a circuit consisting of a copper coil, wires, an open switch and a sensitive ammeter.A magnet is pushed into the coil.Which of these occur during this experiment? A) Current flow and deflection in ammeter. B) E.M.F induced and deflection in ammeter. C) E.m.f induced, current flow and deflection in ammeter. D) None of them. Show Answer Correct Answer: D) None of them. 45. According to Lenz's Law, the direction of the induced current in a closed loop is such that it will ..... A) Double the magnetic flux. B) Enhance the change in magnetic flux. C) Have no effect on the magnetic flux. D) Oppose the change in magnetic flux. Show Answer Correct Answer: D) Oppose the change in magnetic flux. 46. Who showed that an electric current can be produced in an conductor with the help of moving magnet??? A) Issac Newton. B) Albert Einstein. C) Michael Faraday. D) Homi J. Bhabha. Show Answer Correct Answer: C) Michael Faraday. 47. A coil of 100 turns has a magnetic flux of 0.02 Wb passing through it. If the flux changes to 0.08 Wb in 0.1 seconds, the induced e.m.f. is A) 6 V. B) 60 V. C) 600 V. D) 6000 V. Show Answer Correct Answer: B) 60 V. 48. What is the equation for electrical power A) Electrical power = current / p.d.P = I / V. B) Electrical power = current x p.d.P = I x V. C) Electrical power = current + p.d.P = I + V. D) None of the above. Show Answer Correct Answer: B) Electrical power = current x p.d.P = I x V. 49. The current through a 1 mH coil drops from 5A to 3A in 3*10$^{-2}$ second.The emf developed in the coil is ..... A) 8V. B) 2V. C) 8*10$^{-6}$ V. D) 2*10$^{-6}$ V. Show Answer Correct Answer: B) 2V. 50. When current increases in a coil, the induced current will be A) Clockwise. B) Anticlockwise. C) In the same direction. D) In the opposite direction. Show Answer Correct Answer: D) In the opposite direction. 51. You have an imaginary, closed box. If you measure the total electric flux going out of the box and find that it is zero, what can you say for sure? A) The electric field is zero everywhere inside the box. B) The net (total) charge inside the box is zero. C) There are absolutely no charges inside the box. D) The box must be made of a conducting material. Show Answer Correct Answer: B) The net (total) charge inside the box is zero. 52. If a secondary coil has 40 turns, and, a primary coil with 20 turns is charged with 50 V of potential difference, then potential difference in secondary coil would be A) 100 V in secondary coil. B) 50 V in secondary coil. C) 25 V in secondary coil. D) 60 V in secondary coil. Show Answer Correct Answer: A) 100 V in secondary coil. 53. The north pole of a bar magnet is moving towards the coil along the axis passing through the centre of coil and perpendicular to the plane of coil. The direction of induced current in the coil when viewed from the opposite direction of the motion of the magnet is A) No current in the coil. B) Clockwise. C) Data insufficient. D) Anticlockwise. Show Answer Correct Answer: B) Clockwise. 54. Sebuah dinamo sepeda terdiri atas 1000 lilitan. Dinamo dihubungkan dengan roda sedemikian sehingga putaran roda sama dengan putaran poros kumparan. Ketika roda berputar dengan 30 putaran per menit, ternyata tegangan yang dihasilkan adalah 10 V. Jika luas penampang kumparan pada dinamo 20 cm$^{2}$, maka kuat medan magnet yang digunakan pada dinamo tersebut adalah ..... A) 0, 5 T. B) 1, 1 T. C) 0, 2 T. D) 2, 2 T. E) 0, 3 T. Show Answer Correct Answer: B) 1, 1 T. 55. A transformer has 5 turns on the secondary side and 25 turns on the primary side. If the primary voltage is 110 v what is the secondary voltage? A) 550 V. B) 220 V. C) 55 V. D) 22 V. Show Answer Correct Answer: D) 22 V. 56. How would you reverse the direction of the current flowing through the coil in Faraday's experiment? A) Move the magnet through the coil faster. B) Use a magnet of opposite polarity. C) Use a larger magnet. D) Reverse the magnet's direction. Show Answer Correct Answer: D) Reverse the magnet's direction. 57. To repel means ..... A) A force created by magnets that pulls some metals. B) An object able to pull some metals towards itself. C) To Pull towards. D) To push away. Show Answer Correct Answer: D) To push away. 58. How does the back emf compare to the original emf? A) It may be many times greater than the original emf. B) It is always less than the original emf. C) It is equal to the original emf. D) It is unrelated to the original emf. Show Answer Correct Answer: A) It may be many times greater than the original emf. 59. How is the energy stored in an inductor when a current is flowing through it? A) Stored in the power supply by directing the current back to the power supply. B) Stored in the current flowing though the inductor. C) Stored in the electric field created by the current. D) Stored in the magnetic field created by the current. Show Answer Correct Answer: D) Stored in the magnetic field created by the current. 60. Assume primary has 240 turns and secondary has 60 turns. Primary is connected with 120V AC power supply. What is the voltage on the secondary? A) 30 V. B) 120V. C) 2 V. D) 0.333 V. Show Answer Correct Answer: A) 30 V. ← PreviousNext →Related QuizzesScience QuizzesClass 12 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 8 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books