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 5 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 5 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Primary winding:400 turnsSecondary winding:200 turnsIf there are 240V and 8A on the primary, the secondary will have ..... A) 240V at 4A. B) 120V at 4A. C) 240V at 16A. D) 120V at 16A. Show Answer Correct Answer: D) 120V at 16A. 2. By increasing the number of turns in a coil, the current in the wire A) Remains the same. B) Becomes zero. C) Decreases. D) Increases. Show Answer Correct Answer: D) Increases. 3. In a simple generator, what happens when the coil rotates faster? A) The induced voltage decreases. B) The induced voltage increases. C) The current stops flowing. D) The magnetic field strength increases. Show Answer Correct Answer: B) The induced voltage increases. 4. What does Faraday's Law state? A) Electric fields are independent of magnetic fields. B) Induced current is always constant. C) Magnetic fields do not affect electric currents. D) Induced emf is proportional to the rate of change of magnetic flux. Show Answer Correct Answer: D) Induced emf is proportional to the rate of change of magnetic flux. 5. The condition for the phenomena of electromagnetic induction is that there must be a relative motion between A) The galvanometer and magnet. B) The coil of wire and galvanometer. C) The coil of wire and magnet. D) The magnet and galvanometer. Show Answer Correct Answer: C) The coil of wire and magnet. 6. A solenoid of length $l$ A) $\frac{\mu_0N^2A}{l}$. B) $\mu_0N^2A$. C) $\mu_0N^2\pi r$. D) $\frac{\mu_0N^2\pi r}{2}$. Show Answer Correct Answer: A) $\frac{\mu_0N^2A}{l}$. 7. Increasing the magnet's speed affects the electric field by: A) Decreasing the electric field strength. B) Increasing the electric field strength. C) No effect on the electric field. D) Reversing the direction of the electric field. Show Answer Correct Answer: B) Increasing the electric field strength. 8. Magnetic flux involves ..... and ..... A) Magnetic field and surface area. B) Induction and surface area. C) Magnetic field and induction. D) Electromagnetic induction and surface area. Show Answer Correct Answer: A) Magnetic field and surface area. 9. What is the unit of magnetic flux A) T. B) Wb/m$^{2}$. C) W. D) Wb. Show Answer Correct Answer: D) Wb. 10. Which direction does a magnetic field point? A) The direction of the force on an electron. B) The direction of the force on the north side of a magnet. C) The direction of the force on the south side of a magnet. D) The direction of the force on a coil of wire. Show Answer Correct Answer: B) The direction of the force on the north side of a magnet. 11. In electromagnetic induction, what is the role of a changing magnetic field? A) It decreases voltage. B) It creates a magnetic pole. C) It increases resistance. D) It induces an electric current. Show Answer Correct Answer: D) It induces an electric current. 12. A metal ring is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet is A) More than g. B) Equal to g. C) Less than g. D) None of these. Show Answer Correct Answer: C) Less than g. 13. If the number of turns in coil is increased to 3 times, its self inductance will ..... A) Increase to 9 times. B) No change. C) Decrease to 9 times. D) 3 times. Show Answer Correct Answer: A) Increase to 9 times. 14. Passing a current through a solenoid will produce A) Nothing is produced. B) A magnetic field. C) An electric field. D) A current field. Show Answer Correct Answer: B) A magnetic field. 15. A Conducting circular loop is placed in a uniform Magnetic field, B= 0.025 T with its plane perpendicular to the loop. The radius of the loop is made to shrink at a constant rate of 1 mm/s. The induced emf when the radius is 2 cm is A) $\frac{\pi\mu V}{2}$. B) $\pi\mu V$. C) $2\mu V$. D) $2\pi\mu V$. Show Answer Correct Answer: B) $\pi\mu V$. 16. What is electromagnetic induction in a transformer? A) The current in one coil (of the transformer) causes/induces a voltage (p.d.) in the second coil. B) The voltage (p.d.) in one coil (of the transformer) causes/induces a voltage (p.d.) in the second coil. C) All the above. D) None of the above. Show Answer Correct Answer: B) The voltage (p.d.) in one coil (of the transformer) causes/induces a voltage (p.d.) in the second coil. 17. Observe:Check that Show loop data is on. Move the wire loop up, away from the magnet. Is this motion of the loop equivalent to the magnet moving up or down? A) No. B) Only if the magnet is stationary. C) Yes. D) It depends on the speed of the loop. E) Only if the loop is made of a specific material. Show Answer Correct Answer: C) Yes. 18. ..... rule can be used to determine the direction of the induced current produced. A) Right Hand Palm. B) Right Hand Grip. C) All the above. D) None of the above. Show Answer Correct Answer: B) Right Hand Grip. 19. Fleming's Hand Rules were originated by John Ambrose Fleming, in the late 19th century, as a simple way of working out the direction of motion in an electric motor, or the direction of electric current in an electric generator. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 20. Magnetic flux is measured in A) Webers. B) Teslas. C) Coulombs. D) Farads. Show Answer Correct Answer: A) Webers. 21. What happen to magnetic flux if area of plane in the magnetic field decreases? A) Magnetic flux remains constant. B) Magnetic flux decreases. C) Magnetic flux becomes zero. D) Magnetic flux increases. Show Answer Correct Answer: B) Magnetic flux decreases. 22. What is the relationship between electricity and magnetism? Choose the best answer. A) Electricity is a form of magnetism. B) Magnetism is a form of electricity. C) They are two forms of the same basic force. D) They are not closely related at all. Show Answer Correct Answer: C) They are two forms of the same basic force. 23. A straight wire, 0.5 m long, is moved straight up at a speed of 20 m/s through a 0.4-Tmagnetic field pointed in the horizontal direction.The wire is part of a circuit of total resistance of 6.0 Ohms' . What is the current in the circuit? A) 0.4 A. B) 0.7 A. C) 0.3 A. D) 0 A. Show Answer Correct Answer: B) 0.7 A. 24. What are the applications of electromagnetic induction in everyday life? A) Batteries. B) Wind turbines. C) Applications of electromagnetic induction include electric generators, transformers, induction cooktops, and MRI machines. D) Solar panels. Show Answer Correct Answer: C) Applications of electromagnetic induction include electric generators, transformers, induction cooktops, and MRI machines. 25. Faraday's law of electromagnetic induction states that the electromotive force (emf) induced in a conductor is proportional to A) The rate of change of magnetic flux density. B) The change of magnetic flux density. C) The change of magnetic flux linkage. D) The rate of change of magnetic flux linkage. Show Answer Correct Answer: D) The rate of change of magnetic flux linkage. 26. What does Fleming's Right Hand Rule help determine? A) Speed of electric currents. B) Resistance in circuits. C) Strength of magnetic fields. D) Direction of induced emf. Show Answer Correct Answer: D) Direction of induced emf. 27. Faraday's Law is used to A) Explain how an induced e.m.f. is produced. B) Deduce the magnitude of the induced e.m.f. C) Explain how a changing magnetic field is produced. D) Deduce the direction of the induced current. Show Answer Correct Answer: B) Deduce the magnitude of the induced e.m.f. 28. When a constant current of 5.0 A flows in a 400 turns solenoid of length, l and cross sectional area A, emf is induced in the coil. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 29. What is the purpose of Lenz's law? A) To create a magnetic field. B) To amplify the induced current. C) To reduce the induced current. D) To oppose the change in magnetic flux. Show Answer Correct Answer: D) To oppose the change in magnetic flux. 30. Which device uses slip rings? A) An a.c. generator. B) A solenoid. C) A d.c. generator. D) A cathode-ray tube. Show Answer Correct Answer: A) An a.c. generator. 31. When a metal wire moves up, cutting a magnetic field, an electromotive force (e.m.f.) is induced across the wire. Which change affects the magnitude of the induced e.m.f.? A) Using a thicker wire. B) Moving the wire up at a faster speed. C) Using a wire made from a different metal. D) Moving the wire down at the same speed. Show Answer Correct Answer: B) Moving the wire up at a faster speed. 32. In an experiment, a coil is moved through a magnetic field. What happens to the induced current if the speed of the coil's movement is doubled? A) The induced current remains the same. B) The induced current is quadrupled. C) The induced current is doubled. D) The induced current is halved. Show Answer Correct Answer: C) The induced current is doubled. 33. The production of a voltage across an inductor as a result of its own expanding or contracting magnetic field is called ..... A) Faraday's second law. B) Self-inductance. C) Flux density. D) Counter emf. Show Answer Correct Answer: B) Self-inductance. 34. If an inductor has N turns and is magnetic flux through its each turn when current I is flowing, then self-inductance L is given by formula: A) $N\phi$. B) $N\phi I$. C) $\frac{N\phi}{I}$. D) $\frac{I}{N\phi}$. Show Answer Correct Answer: C) $\frac{N\phi}{I}$. 35. Explore:Try moving the loop slowly, then fast. Observe the magnitude of the current as you do this. How does the speed of the loop affect the current? A) The current increases with speed. B) The current decreases with speed. C) The current remains constant regardless of speed. D) The current fluctuates randomly with speed. Show Answer Correct Answer: A) The current increases with speed. 36. A generator is used to light a bulb. Energy for lighting the bulb actually comes from a A) Coil or wire. B) Mechanical intput to the generator. C) Magnet in the generator. D) Plug where the generator is connected to the wall. Show Answer Correct Answer: B) Mechanical intput to the generator. 37. In an L-R circuit, time constant is that time in which current grows from zero to the value (Where is the steady state current): A) . B) 0.371. C) 0.50. D) 0.63. Show Answer Correct Answer: D) 0.63. 38. What is the direction of force induced by a current carrying conductor in a magnetic field according to Fleming's left-hand rule? A) Palm. B) Middle finger. C) Index finger. D) Thumb. Show Answer Correct Answer: D) Thumb. 39. Which of the following is a positive facial expression? A) Looking somewhere else. B) Nodding while listening. C) Staring hard. D) Wrinkled forehead. Show Answer Correct Answer: B) Nodding while listening. 40. A solenoid with a length of 20.0 cm has a total of 1260 turns of wire. If its cross-sectional area is 12.0 cm$^{2}$, the inductance of solenoid is A) 18.0 mH. B) 12.0 mH. C) 14.0 mH. D) 16.0 mH. Show Answer Correct Answer: B) 12.0 mH. 41. What is an advantage of transmitting electricity at a high voltage? A) It is faster. B) Less energy is wasted. C) Less equipment is needed. D) It is safer. Show Answer Correct Answer: B) Less energy is wasted. 42. Identify the paramagnetic substance A) Iron. B) Nickel. C) Aluminium. D) Hydrogen. Show Answer Correct Answer: C) Aluminium. 43. What is the role of magnetic flux in electromagnetic induction? A) Magnetic flux repels the magnetic field, reducing induction. B) Magnetic flux creates a barrier preventing induction. C) Magnetic flux links the magnetic field with the conductor, inducing an electromotive force (EMF) and generating an electric current. D) Magnetic flux has no impact on electromagnetic induction. Show Answer Correct Answer: C) Magnetic flux links the magnetic field with the conductor, inducing an electromotive force (EMF) and generating an electric current. 44. An ideal solenoid 50 cm long has 4000 loops wound on it. Compute the magnetic field, B, in its interior when a current of 0.25 A flows through it. A) 0.63 mT. B) 2.5 mT. C) 10.0 mT. D) 2.5 x 10$^{-5}$ T. Show Answer Correct Answer: B) 2.5 mT. 45. Which of these is LENZ'S LAW A) The direction of the induced emf is always in the opposite direction to the applied emf. B) The direction of the induced emf is always increasing the change that produced it. C) The direction of the induced emf is always in the same direction to the applied emf. D) The direction of the induced emf is always opposing the change that produced it. Show Answer Correct Answer: D) The direction of the induced emf is always opposing the change that produced it. 46. Which of the following is a real-world application of electromagnetic induction? A) Hydraulic press. B) Gasoline engine. C) Solar panels. D) Wind turbines. Show Answer Correct Answer: D) Wind turbines. 47. The measuring unit of emf A) T. B) M. C) V. D) A. Show Answer Correct Answer: C) V. 48. Electric charges must ..... in order to create an observable magnetic field. A) Exist. B) Be stationary. C) Disappear. D) Be moving. Show Answer Correct Answer: D) Be moving. 49. When a coil rotates in a magnetic field, the induced current in it A) Becomes zero. B) Becomes maximum. C) Continuously changes direction. D) Remains same. Show Answer Correct Answer: C) Continuously changes direction. 50. How does resistance affect induced current in a circuit? A) Higher resistance increases the induced current for a given induced voltage. B) Lower resistance increases the induced current but only at high voltages. C) Higher resistance in a circuit reduces the induced current for a given induced voltage. D) Resistance has no effect on the induced current in a circuit. Show Answer Correct Answer: C) Higher resistance in a circuit reduces the induced current for a given induced voltage. 51. What happens to a coil of wire when a magnet is moved repeatedly inside the coil? A) Nothing happens. An electric current ONLY forms when a wire is moved between two magnets. B) The magnet begins to lose its magnetic field. C) The coil of wire loses its magnetic properties because of the motion of the magnet. D) An electric current is induced in the coil of wire. Show Answer Correct Answer: D) An electric current is induced in the coil of wire. 52. When there is a change in the magnetic field in a closed loop of wire A) A voltage is induced in the wire. B) Current is made to flow in the loop of wire. C) Electromagnetic induction occurs. D) All of these. Show Answer Correct Answer: D) All of these. 53. What is induced EMF and how is it generated? A) Induced EMF is created by a constant magnetic field. B) Induced EMF is generated by a change in magnetic flux through a conductor. C) Induced EMF occurs only in superconductors. D) Induced EMF is unrelated to magnetic fields. Show Answer Correct Answer: B) Induced EMF is generated by a change in magnetic flux through a conductor. 54. What is the contribution of Joseph Henry to the world of electromagnetism? A) Formulated Lenz's law. B) Discovered the electromagnetic phenomenon of self-inductance. C) Discovered electrons. D) Concluded that lightning contains electricity. Show Answer Correct Answer: B) Discovered the electromagnetic phenomenon of self-inductance. 55. What is the principle behind AC generators? A) Thermal expansion. B) The principle behind AC generators is electromagnetic induction. C) Chemical reaction. D) Mechanical friction. Show Answer Correct Answer: B) The principle behind AC generators is electromagnetic induction. 56. What is the unit of self-inductance? A) Volt. B) Ampere. C) Ohm. D) Henry. Show Answer Correct Answer: D) Henry. 57. What factors affect the magnitude of induced EMF according to Faraday's Law? A) The rate of change of magnetic flux, the number of turns in the coil, and the area of the coil. B) The temperature of the coil. C) The strength of the electric field. D) The resistance of the circuit. Show Answer Correct Answer: A) The rate of change of magnetic flux, the number of turns in the coil, and the area of the coil. 58. Why transformers work with A.C. current but not D.C. A) C current is weak. B) C current is powerful. C) C current produces changing magnetic field. D) C current produces changing magnetic field. Show Answer Correct Answer: C) C current produces changing magnetic field. 59. A circular coil carrying a current of radius R and number of turns N and if all the three that is the current I, radius R and number of turns N are doubled, then magnetic field at its centre becomes A) One fourth. B) 4 times. C) Half. D) Double. Show Answer Correct Answer: D) Double. 60. A lamp rated at 12 V 60 W is connected to the secondary coil of a step-down transformer and is at full brightness. The primary coil is connected to a supply of 230 V. The transformer is 75% efficient.What is the current in the primary coil? A) 3.75 A. B) 0.25 A. C) 0.35 A. D) 5.0 A. Show Answer Correct Answer: C) 0.35 A. ← 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 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 9 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books