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

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1. In a closed conductive circuit contained in an alternating magnetic field, an induction current arises, the magnetic field of which is directed .....
2. Which of the following explains Electromagnetic Induction?
3. What is/are the factor/s involved in Faraday's Law?
4. 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?
5. According to Lenz's Law, the direction of the induced current in a closed loop is such that it will .....
6. Who showed that an electric current can be produced in an conductor with the help of moving magnet???
7. 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
8. What is the equation for electrical power
9. The current through a 1 mH coil drops from 5A to 3A in 3*10$^{-2}$ second.The emf developed in the coil is .....
10. When current increases in a coil, the induced current will be
11. 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?
12. 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
13. 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
14. 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 .....
15. 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?
16. How would you reverse the direction of the current flowing through the coil in Faraday's experiment?
17. To repel means .....
18. How does the back emf compare to the original emf?
19. How is the energy stored in an inductor when a current is flowing through it?
20. 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?
21. How does the function of a generator relate to the function of a motor?
22. . How to increase the energy stored in an inductor by four times?
23. 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?
24. How does the number of turns in a coil affect the induced electromotive force (emf)?
25. Magnetic fields are created by moving .....