12th Class Physics Quiz Ranking Challenge

1. In an insulator, the forbidden energy gap between the valence band and conduction band is of the order of

2. When light is refracted, which of the following does not change?

3. The magnetic compass is not useful for navigation near the magnetic poles, since

4. The core of transformer is laminated to reduce

5. In Einstein’s picture of Photoelectric emission, the photoelectric emission does not take place by

6. Which of the following is correct for the beam which enters the medium?

7. The cause of the potential barrier in a p-n junction diode is

8. At magnetic poles, the angle of dip is

9. Photoelectric effect can be explained by

10. Which of the following is not due to total internal reflection?

11. In an n-type semiconductor, donor valence band is

12. A capacitor acts as an infinite resistance for

13. The lines of force due to earth’s horizontal magnetic field are

14. In an amplitude modulated wave for audio frequency of 500 cycle/second, the appropriate carrier frquency will be

15. 12 signals each band limited to 5 kHz are to be transmitted by frequency-division multiplexer. If AM-SSB modulation guard band of 1 kHz is used then the bandwidth of multiplexed signal is

16. Television signals are

17. Debye is the unit of

18. A capacitor is charged by a battery. The battery is removed and another identical uncharged capacitor is connected in parallel. The total electrostatic energy of resulting system

19. An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field E. The direction of electric field is now reversed, keeping its magnitude the same. A proton is allowed to fall from rest in it through the same vertical distance h. The time of fall of the electron, in comparison to the time of fall of the proton is

20. Two spheres A and B of exactly same mass are given equal positive and negative charges respectively. Their masses after charging