1. 13Al27 is a stable isotope. 29Al13 is expected to disintegrate by

2. Which of the following does not characterise X-rays?

a) The radiation can ionize gases b) It causes ZnS to florescence

c) Deflected by electric and magnetic fields d) Have wavelengths shorter than ultraviolet rays

3. The nucleus resulting from 238U92 after successive loss of tw alpha and four beta particles is

a)238 TH 90 b) 230 Pu 94 c) 230 Ra 88 d) 230 U 92

4. Nuclear reactions accompanied with the emission of neutron(s) is

a) 13 Al 27 + 2 He 4 15 P 30 b) 6 C 12 + 1H1 7N13

c) 15P30 14Si30 + +1e0 d) 96Am241 + 2He4 97Bk241 + +1e 0

5. The radiations from a naturally occurring radioactive substance as seen after deflection by a magnetic field in one direction are

a) definitely

6. The increasing order for the values of e/m (charge/mass) for electron(e), proton(p), neutron(n) and alpha particle() is

a) e,p,n,

7. An isotone of 76Ge32 is

a) 77 Ge 32 b) 77 As 33 c) 77Se 34 d) 77Se 36

8. If Uranium (mass number 238 and atomic number 92) emits an – particle, the product has mass number and atomic number

a) 236and 92 b) 234and90 c) 238and90 d) 236and90

9. Which of the following in an isotope of 32 Ge 76 ?

a) 33 As 77 b) 32 Ge 77 c) 34 Se 77 d) 35 Br 80

10. The half-life of a radiative nuclide is 100 years. What is the disintegration constant(in year -1)?

a) 6.93*103 b) 6.93*102 c)6.93*10-3 d)6.93

11. Which of the following nuclide is unstable?

a) 5B10 b) 4Be10 c) 7N4 d) 8O16

12. Element zMA emits one (alpha) particle followed by two (beta) particles. Which of the following is the daughter element?

a) Z-2 MA-4 b) Z-2 M A c) Z M A-4 d) Z+2 M A-4

13. The activity of a radiative element is 2*10 10 disintegrations per second. After 10 minutes, the activity is reduced to 2*109 disintegrations per second. The disintegration constant of the radioactive element is (in min-1)

a)2 b) 2.303 c) 10 d) 0.2303

14. The units of radioactivity is

a) Fermi b) Farad c) Curie d) Hertz

15. Radioactivity of an isotope falls to 1/8 of its original value in 48 days. Its half-life period(in days) is

a) 48 b) 16 c) 12 d) 8

16. The radius of the nucleus is related to the mass number ‘A’ by

a) R = R0A1/2 b) R = R0A c) R = R0A2 d) R= R0A1/3

17. Which of the following has magic number of protons and neutrons?

18. The activity of a radioactive nuclide(X100) is 6.023 curie. If its disintegration constant is 3.7*104 sec -1, the mass of X is

19. The atomic number of a radioactive element increases by one unit in :

a) alpha emission d) beta emission c) gamma emission d) electron capture

20. Sulphr -35 (34.96903 a. m. u) emits a particle. But no ray. The product is chlorine 35(34.96885 a.m.u.).

The maximum energy of the particle emitted is

a) 0.00018 MeV b) 930MeV c) 0.16758 MeV d) 1.6758 MeV

21. The half-life of a radioactive isotope is 3 hours. The value of its disintegration constant is

a) 0.3 hour-1 b) 0.693 hour -1 c) 0.231 hour -1 d) 0.231 min -1

22. Which of the following is used to bomnard 13 Al 27 to give 15 P30 and a neutron.

a) Proton b) –particle c) 3.5 hrs d) 4 hrs

23. Half-life of a radioactive substance is 1 hour. The time taken for disintegration of 87.5% substance is

a) 2 hrs b) 3 hrs c) 3.5 hrs d) 4 hrs

24. Which of the following is a magic number?

a) 54 b) 10 c) 20 d) 18

25. Energy is released when 1 mg of mass is annihilated is

a) 10 13 J b) 10 10 J c) 10 7 J d) none of these