This quiz works best with JavaScript enabled. Home > Class 12 > Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction – Quiz 12 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 12 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is the purpose of Lenz's law? A) To oppose the change in magnetic flux. B) To create a magnetic field. C) To reduce the induced current. D) To amplify the induced current. Show Answer Correct Answer: A) To oppose the change in magnetic flux. 2. Which device uses slip rings? A) A cathode-ray tube. B) A d.c. generator. C) An a.c. generator. D) A solenoid. Show Answer Correct Answer: C) An a.c. generator. 3. 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) Moving the wire down at the same speed. B) Moving the wire up at a faster speed. C) Using a thicker wire. D) Using a wire made from a different metal. Show Answer Correct Answer: B) Moving the wire up at a faster speed. 4. 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 is halved. B) The induced current remains the same. C) The induced current is doubled. D) The induced current is quadrupled. Show Answer Correct Answer: C) The induced current is doubled. 5. The production of a voltage across an inductor as a result of its own expanding or contracting magnetic field is called ..... A) Flux density. B) Self-inductance. C) Counter emf. D) Faraday's second law. Show Answer Correct Answer: B) Self-inductance. 6. 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) $\frac{I}{N\phi}$. B) $N\phi$. C) $\frac{N\phi}{I}$. D) $N\phi I$. Show Answer Correct Answer: C) $\frac{N\phi}{I}$. 7. 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. 8. 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. 9. 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) 0.63. B) 0.50. C) 0.371. D) . Show Answer Correct Answer: A) 0.63. 10. What is the direction of force induced by a current carrying conductor in a magnetic field according to Fleming's left-hand rule? A) Thumb. B) Index finger. C) Palm. D) Middle finger. Show Answer Correct Answer: A) Thumb. 11. Which of the following is a positive facial expression? A) Staring hard. B) Wrinkled forehead. C) Looking somewhere else. D) Nodding while listening. Show Answer Correct Answer: D) Nodding while listening. 12. 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) 12.0 mH. B) 14.0 mH. C) 16.0 mH. D) 18.0 mH. Show Answer Correct Answer: A) 12.0 mH. 13. What is an advantage of transmitting electricity at a high voltage? A) It is faster. B) It is safer. C) Less energy is wasted. D) Less equipment is needed. Show Answer Correct Answer: C) Less energy is wasted. 14. Identify the paramagnetic substance A) Iron. B) Aluminium. C) Nickel. D) Hydrogen. Show Answer Correct Answer: B) Aluminium. 15. 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. 16. 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) 10.0 mT. B) 2.5 mT. C) 0.63 mT. D) 2.5 x 10$^{-5}$ T. Show Answer Correct Answer: B) 2.5 mT. 17. 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 opposing 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 increasing the change that produced it. Show Answer Correct Answer: B) The direction of the induced emf is always opposing the change that produced it. 18. Which of the following is a real-world application of electromagnetic induction? A) Solar panels. B) Wind turbines. C) Hydraulic press. D) Gasoline engine. Show Answer Correct Answer: B) Wind turbines. 19. The measuring unit of emf A) V. B) A. C) M. D) T. Show Answer Correct Answer: A) V. 20. Electric charges must ..... in order to create an observable magnetic field. A) Exist. B) Be moving. C) Be stationary. D) Disappear. Show Answer Correct Answer: B) Be moving. 21. When a coil rotates in a magnetic field, the induced current in it A) Continuously changes direction. B) Remains same. C) Becomes zero. D) Becomes maximum. Show Answer Correct Answer: A) Continuously changes direction. 22. How does resistance affect induced current in a circuit? A) Higher resistance in a circuit reduces the induced current for a given induced voltage. B) Higher resistance increases the induced current for a given induced voltage. C) Resistance has no effect on the induced current in a circuit. D) Lower resistance increases the induced current but only at high voltages. Show Answer Correct Answer: A) Higher resistance in a circuit reduces the induced current for a given induced voltage. 23. What happens to a coil of wire when a magnet is moved repeatedly inside the coil? A) The coil of wire loses its magnetic properties because of the motion of the magnet. B) The magnet begins to lose its magnetic field. C) An electric current is induced in the coil of wire. D) Nothing happens. An electric current ONLY forms when a wire is moved between two magnets. Show Answer Correct Answer: C) An electric current is induced in the coil of wire. 24. 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. 25. What is induced EMF and how is it generated? A) Induced EMF is unrelated to magnetic fields. B) Induced EMF occurs only in superconductors. C) Induced EMF is created by a constant magnetic field. D) Induced EMF is generated by a change in magnetic flux through a conductor. Show Answer Correct Answer: D) Induced EMF is generated by a change in magnetic flux through a conductor. ← 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