Class 12 Physics (Part I) Chapter 6 Electromagnetic Induction Quiz 33 (25 MCQs)

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1. A straight wire carrying a 9.0 A current is in a uniform magnetic field oriented at right angles to the wire. When 75 cm of wire is in the field, the force on the wire is 1.2 N. What is the strength of the magnetic field (B)?
2. The unit of magnetic flux is
3. How can you increase the EMF induced in a wire?
4. Which of the following must change if there is to be an induced emf?
5. How does the electric field change as the magnet approaches the loop?
6. Based on the observations you have made, what is Faraday's law?
7. What would happen if you broke a bar magnet into 8 pieces?
8. A metallic wire having the length of 2 metre and weight of 4 x10-3 newton is found to remain at rest in a uniform and transverse magnetic field of 2x10-4 Tesla the current flowing through the wires
9. What is the unit of inductance and how is it calculated?
10. In general, how do the current and electric field relate to the change in magnetic flux?
11. Whenever there is a relative motion between a coil and a magnet, the magnitude of induced emf set up in the coil does not depend upon the
12. What happens to the induced electromotive force (emf) if the speed of the movement of a conductor in a magnetic field is doubled?
13. A step-up transformer produces a 60 V a.c. output from a 12 V a.c. input. There are 50 turns on the secondary coil. How many turns are there on the primary coil?
14. A permanent horseshoe magnet is mounted so that the magnetic field lines are vertical. If a student passes a straight wire between the poles and pulls it toward herself, the current flow through the wire is from right to left. Which is the north pole of the magnet?
15. When the coil of a generator is rotated at a rate of 5 Hz, the maximum EMF generated is 2.5 V. If the coil is now rotated at 10 Hz, the maximum EMF generated is:
16. Phenomenon of generation of induced electromotive force and induced current a conductor as a result of the variation of the magnetic flux lines that intercepted by the conductor .
17. What does electromagnetism mean?
18. Mutual inductance between two coils depends on
19. How can the direction of an induced potential be reversed?
20. No EMF is induced when?
21. Which of the two and ammeter or voltmeter has a greater resistance
22. When the number of coils in a magnet is increased, what happens to the magnitude of the current?
23. What happens to the current in a coil while accelerating a magnet inside it?
24. What is the national grid?
25. The coil in a d.c. motor is connected to a split-ring commutator. What is the purpose of the split-ring commutator?