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 11 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 11 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. How does the function of a generator relate to the function of a motor? A) They are the same. B) They are opposites. C) They both work the same way. D) They are not related at all. Show Answer Correct Answer: B) They are opposites. 2. . How to increase the energy stored in an inductor by four times? A) By doubling the inductance. B) By doubling the current. C) By making current 2 times. D) This is not possible. Show Answer Correct Answer: B) By doubling the current. 3. A class is designing a d.c. motor. To achieve a greater turning effect, three suggestions are made. 1. Have a larger current in the coil of the motor. 2. Have a stronger magnet in the motor. 3. Put a larger number of turns on the coil. Which suggestions will help to increase the turning effect? A) 1, 2 and 3. B) 1 and 2 only. C) 1 and 3 only. D) 2 and 3 only. Show Answer Correct Answer: A) 1, 2 and 3. 4. How does the number of turns in a coil affect the induced electromotive force (emf)? A) It increases. B) It decreases. C) It creates a magnetic field. D) It has no effect. Show Answer Correct Answer: A) It increases. 5. Magnetic fields are created by moving ..... A) Electric Charges. B) Protons. C) Metals. D) Atoms. Show Answer Correct Answer: A) Electric Charges. 6. What is the purpose of using a commutator in an AC generator? A) To convert AC to DC. B) To regulate the frequency of the generated AC. C) To increase the voltage output. D) To reduce the efficiency of the generator. Show Answer Correct Answer: A) To convert AC to DC. 7. AC generator converts: A) Heat energy to mechanical energy. B) Chemical energy to electrical energy. C) Mechanical energy to electrical energy. D) Electrical energy to mechanical energy. Show Answer Correct Answer: C) Mechanical energy to electrical energy. 8. 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) 0.75 A. D) 0.8 A. E) 3.2 A. Show Answer Correct Answer: B) 1.5 A. 9. 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. 10. 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. 11. 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. 12. 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. 13. 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. 14. 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. 15. 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) 100 W. C) 50 W. D) 75 W. Show Answer Correct Answer: B) 100 W. 16. 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. 17. 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. 18. Lenz's law states that the direction of the induced current is such that it A) Follows the direction of the magnetic field. B) Opposes the change in magnetic flux. C) Enhances the change in magnetic flux. D) Is always in the same direction as the applied current. Show Answer Correct Answer: B) Opposes the change in magnetic flux. 19. 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 fluctuates. B) The current remains constant. C) The current decreases. D) The current increases. Show Answer Correct Answer: D) The current increases. 20. 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. 21. How does changing the magnetic field affect induced EMF? A) Changing the magnetic field induces EMF proportional to the rate of change. B) Changing the magnetic field has no effect on EMF. C) EMF decreases as the magnetic field changes. D) Induced EMF is constant regardless of magnetic field changes. Show Answer Correct Answer: A) Changing the magnetic field induces EMF proportional to the rate of change. 22. Which of these is NOT a part of a DC Generator. A) Commutator. B) Slip rings. C) Brushes. D) Stator. Show Answer Correct Answer: B) Slip rings. 23. 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. 24. 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) 1/16. B) 1/8. C) 1/32. D) 15/16. Show Answer Correct Answer: D) 15/16. 25. 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. 26. 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%. 27. 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) 12 m. B) 10 m. C) 50 m. D) 23 m. Show Answer Correct Answer: D) 23 m. 28. 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. 29. Changing magnetic fields can set up current loops in nearby metal bodies. they dissipate electrical energy as heat, such currents are called A) Faraday Currents. B) Henry Currents. C) Eddy currents. D) Inductance current. Show Answer Correct Answer: C) Eddy currents. 30. 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. 31. Click Forward and wait until the magnet gets to the top. How many field lines are passing through the loop now? A) 5. B) 15. C) 0. D) 10. Show Answer Correct Answer: D) 10. 32. The current passing through a choke coil of self inductance 5 H is decreasing at the rate of 2 A/s. The e.m.f.developed across the coil is A) -5. B) 10. C) 5. D) -10. Show Answer Correct Answer: B) 10. 33. Doubling the diameter of a loop of wire produces, what will happen for emf, assuming all other factors are constant A) Emf will increase to four time. B) Emf will decrease to half. C) Emf will decrease to quarter. D) Emf will increase to double. Show Answer Correct Answer: A) Emf will increase to four time. 34. Define magnetic flux and its unit. A) Magnetic flux is measured in Teslas (T). B) Magnetic flux is defined as the force exerted by a magnet. C) Magnetic flux is measured in Amperes (A). D) Magnetic flux is measured in Webers (Wb). Show Answer Correct Answer: D) Magnetic flux is measured in Webers (Wb). 35. What causes the potential difference to be induced in the wire? A) The temperature of the wire. B) The movement of the wire through a magnetic field. C) The strength of the electric current. D) The length of the wire. Show Answer Correct Answer: B) The movement of the wire through a magnetic field. 36. The function of a transformer is to ..... A) Raise and lower the apparent power levels. B) Transfer DC voltage from the primary winding to the secondary winding. C) Increase or decrease A.C voltage or A.C current levels. D) Transform mechanical energy into electrical energy. Show Answer Correct Answer: C) Increase or decrease A.C voltage or A.C current levels. 37. The direction of the induced current in a conductor moving through a magnetic field can be determined using A) Faraday's law. B) Current rule. C) Fleming's right-hand rule. D) Fleming's left-hand rule. Show Answer Correct Answer: C) Fleming's right-hand rule. 38. The core of a transformer is laminated to reduceeddy currentsresistive losseshysteresis losses A) 1, 2, 3. B) 3 only. C) 1, 2. D) 1 only. Show Answer Correct Answer: D) 1 only. 39. Which law states that the induced current is proportional to the change of magnetic flux? A) Ampere's law. B) Faraday's law. C) Gauss' law. D) Lenz's law. Show Answer Correct Answer: B) Faraday's law. 40. What happens to the induced emf when the speed of movement increases? A) Induced emf becomes zero. B) Induced emf decreases. C) Induced emf increases. D) Induced emf remains constant. Show Answer Correct Answer: C) Induced emf increases. 41. A circular loop is placed in a decreasing magnetic field. What happens to the induced current in the loop? A) It remains zero. B) It flows into the page. C) It flows counterclockwise. D) It flows clockwise. Show Answer Correct Answer: D) It flows clockwise. 42. A current of 2.5 A flows through a coil of inductance 5 H. The magnetic flux linked with the coil is A) 12.5 Wb. B) Zero. C) 0.5 Wb. D) 2 Wb. Show Answer Correct Answer: A) 12.5 Wb. 43. Who is known for the invention of the motor, generator, and transformer? A) James Clerk Maxwell. B) Thomas Edison. C) Michael Faraday. D) Nikola Tesla. Show Answer Correct Answer: C) Michael Faraday. 44. Which component forms part of a d.c. motor but not a simple moving coil a.c. generator? A) The coil. B) The brushes. C) The magnet. D) The split-ring commutator. Show Answer Correct Answer: D) The split-ring commutator. 45. Explain the concept of mutual induction. A) Mutual induction is the process where a constant current in one coil induces a voltage in an adjacent coil. B) Mutual induction is the process where a changing current in one coil induces a voltage in an adjacent coil. C) Mutual induction is not related to electromagnetic fields. D) Mutual induction only occurs in parallel circuits. Show Answer Correct Answer: B) Mutual induction is the process where a changing current in one coil induces a voltage in an adjacent coil. 46. The dimension of R/L, L/R and RC are A) Frequency, time period and time period. B) Wavelength, Frequency, and time period. C) Frequency, time period and Amplitude. D) None of the above. Show Answer Correct Answer: A) Frequency, time period and time period. 47. What is mutual induction and how does it occur? A) Mutual induction is the process where a changing current in one coil induces a voltage in another nearby coil. B) Mutual induction occurs only in transformers with a fixed current. C) It is the process of a single coil generating a magnetic field without any current change. D) Mutual induction happens when two coils are connected in series with a battery. Show Answer Correct Answer: A) Mutual induction is the process where a changing current in one coil induces a voltage in another nearby coil. 48. The emf induced by motion of conductor across magnetic field is called A) Variable emf. B) Potential Difference. C) Electric potential. D) Motional emf. Show Answer Correct Answer: D) Motional emf. 49. The advantage of an alternating current supply is A) The frequency of the alternating current can be changed easily. B) Alternating current is easier to generate. C) The power of the supply can be maintained at a constant value. D) The voltage of the alternating current can be changed easily. Show Answer Correct Answer: D) The voltage of the alternating current can be changed easily. 50. What is the relationship between current and resistance (for a constant voltage)? A) Current is proportinal to the square root of resistance. B) Current is proportional to the square of resistance. C) Current is proportional to resistance. D) Current is inversely proportional to resistance. Show Answer Correct Answer: D) Current is inversely proportional to resistance. 51. How is e.m.f induced in a circuit according to Faraday's law? A) By changing the magnetic flux linking the circuit. B) By changing the resistance of the circuit. C) By changing the temperature of the circuit. D) By changing the area of the circuit. Show Answer Correct Answer: A) By changing the magnetic flux linking the circuit. 52. A 60 W lamp is connected to a 120 V RMS supply. What is the effective current through the lamp? A) 0.25 A. B) 1.0 A. C) 0.75 A. D) 0.50 A. Show Answer Correct Answer: D) 0.50 A. 53. If the rate of change of magnetic flux is zero, what will be the induced electromotive force? A) Zero. B) Constant. C) Negative. D) Positive. E) None of these. Show Answer Correct Answer: A) Zero. 54. Where is the energy being stored in an inductor carrying a steady current? A) In the electric field of the coil. B) In the power supply. C) In the magnetic field of the coil. D) In the circuit. Show Answer Correct Answer: C) In the magnetic field of the coil. 55. What factor does NOT affect the magnitude of induced voltage? A) Type of conductor material (copper vs. aluminum). B) Strength of the magnetic field. C) Number of turns in the coil. D) Speed of movement. Show Answer Correct Answer: A) Type of conductor material (copper vs. aluminum). 56. A flat circular coil of diameter 30 mm has 500 turns and is situated so that the plane of the coil is perpendicular to a uniform magnetic field of flux density 20 mT. The flux density is reduced steadily to zero in a time of 30 ms. What is the average value of the e.m.f. induced in the coil? A) 940 000V. B) 0.24V. C) 0.94V. D) 240 000V. Show Answer Correct Answer: B) 0.24V. 57. How does Lenz's Law relate to the conservation of energy? A) Lenz's Law allows for the creation of energy from magnetic fields. B) Lenz's Law states that induced currents enhance changes in magnetic fields. C) Lenz's Law demonstrates the conservation of energy by ensuring that induced currents oppose changes in magnetic fields, preventing energy creation. D) Lenz's Law has no relation to energy conservation principles. Show Answer Correct Answer: C) Lenz's Law demonstrates the conservation of energy by ensuring that induced currents oppose changes in magnetic fields, preventing energy creation. 58. Change of current of 1 A s$^{-1}$ causes EMF of 1 V to be equal to A) 1 V m$^{-1}$. B) 1 H. C) 1 J. D) 1 A. Show Answer Correct Answer: B) 1 H. 59. A coil of 10 H inductance and 5Q resistance is connected to 5 volt battery in series. The current in ampere in circuit 2 seconds after switched is on A) (1-e). B) (1-e). C) El. D) E. Show Answer Correct Answer: D) E. 60. A straight conductor of length 0.2 m moves at a speed of 10 m/s perpendicular to a magnetic field of 0.5 T. The induced e.m.f. is A) 0.1 V. B) 100 V. C) 1.0 V. D) 10 V. Show Answer Correct Answer: C) 1.0 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