1. If an a-particle is projected normally through a uniform magnetic field, then the path of the a-particle inside the field will be

2. The process of nuclear fusion in the sun requires

3. A semiconducting device is connected in a series circuit with a battery and a resistance. Current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops to zero. The device may be

4. The penetrating power of X-rays can be increased by

5. Consider the following statements:
1. X-rays show transverse wave characteristics.
2. X-rays can eject electrons from certain metal surfaces
3. X-rays of 0.1 Å are harder than X-rays of 0.2 Å. Which of the statements given above is/are, correct ?

6. Nuclear fusion reactions require very temperatures so as to overcome:

7. Consider the following four particles :
1. Alpha particle 2. Proton
3. Electron 4. Neutron Which of the following is the correct sequence in which their rest-masses increase?

8. Basic scientific principle behind a nuclear reactor is

9. X-rays are electromagnetic radiation whose wavelengths are of the order of:

10. Which one among the following transitions is associated with the largest change in energy in hydrogen atom ?

11. Internet communication uses optical fibre cables because of

12. Repeaters used in telephone links are:

13. Radioactive decay provides an internal source of heat for the earth. This helps in the formation of which type of rocks?

14. The ratio of velocity of X-rays to that of gamma rays

15. Which one of the following is not the characteristic of X-rays?

16. Which of the following is the range of frequency used in optical communication?

17. Sun emits energy in the form of electromagnetic radiation. The following help in the generation of solar energy. Arrange them in the right sequence beginning from the starting of the cycle :
1. Hydrogen is converted to helium at very high temperatures and pressures.
2. The energy finds its way to sun’s surface.
3. A vast quantity of energy is generated by nuclear fusion. Select the correct answer using the code given below.

18. Who among the following has explained the phenomenon of photoelectric effect ?

19. Which one of the following is the unit of activity of a radioactive source?

20. Who among the following built a model steam engine in 1698 called 'Miner's Friend' to drain mines?

21. Electromagnetic radiations are emitted by which of the following?

22. How long does it take light from the sun to reach to the earth (approximately) ?

23. This question consist of two statements, one labelled as the Assertion (A) and the other as ‘Reason (R), You are to examine these two statements carefully and select the answers to these items using the codes given below: Assertion (A) : Radio does not work in a moving train unless aerial is put outside the window.Reason (R) : The train compartment acts as a hollow cylinder and charge is centred which does not allow radio to work.

24. Electron emission from a metallic surface by application of light is known as

25. The neutron, proton, electron and alpha particle are moving with equal kinetic energies. How can the particles be arranged in the increaseing order of their velocities?