As mass number increases. Which of the following does not change? A. mass B. volume C. density D. binding energy 40

A. mass B. volume

C. density D. binding energy
40. 1 rad =

A. 0.01 Sv B. 0.01 Jkg^-1

B. 0.01 rem C. 1 Gy

41. When N¹⁴ is bombarded by α particle, then a proton is emitted. The new element formed is

A. ₈O¹⁷ B. ₉Ne¹⁸

C. ₆C¹² D. ₇N¹⁴
42. The mass density of nucleus varies with its mass number as

A. A B. A²

C. 1/A D. remain constant

43. 
    The minimum temperature necessary for fusion reaction is
    

C. 3 × 10³ K D. 3 × 10² K

A. fast protons B. only slow neutrons

C. only fast neutrons D. fast as well as slow neutrons
45. The correct relation between the packing fraction P and mass number A is

A. P = A/M-A B. P = M-A/A

C. P = A/M+A D. P = M+A/A
46. For making atom bomb, what else is needed except U²³⁵?

A. meson B. neutron

C. proton D. electron
47. The energy emitted per second by the sun is approximately

A. 3.8×10^-26 J B. 3.8×10²⁶ J

C. 3.8×10¹⁴ J D. 3.8×10¹² J
48. When two nuclei of masses x and y respectively fuse to form a nucleus of mass m and some energy is released then

A. X + Y < m B. X + Y > m

C. X – Y = m D. X + Y = m
49. Plutonium decays with half-life of 24000 years. If plutonium is stored for 72000 years, the fraction of it that remains is

A. 1/2 B. 1/3

C. 1/4 D. 1/8
50. Condition for α-decay is:

A. A < 210 and N/Z = 1.6 B. A > 210 and N/Z = 1.6

C. A = 210 and N/Z = 1 D. A = 210 and N/Z = 1.6

51. 
    The SI unit of radioactivity is
    

C. R D. s

A. NZ = 1 B. N/Z = 1

C. N/Z = 1.6 D. N/Z = 1.3
53. For heavier nuclides to be stable the condition is:

A. NZ = 1 B. N/Z = 1

C. N/Z = 1.6 D. N/Z = 1.3

54. 
    Nuclear forces are __________ times stronger than electromagnetic forces
    

C. 60-70 D. 70-80

54. 
    If T_1/2 is half life and T_av is average life of an element then correct relation between them is
    

C. T_av = 1.44 T_1/2 D. T_av = 0.144 T_1/2

54. 
    The fissionable material used in the bomb dropped over the city of Nagasaki in 1945 was
    

C. Pu D. Th

A. isobars B. isotopes of C

C. isotones D. isotopes of N
58. In reaction ₁²H+₁²H ₁³He+₀¹n+Q. what is value of Q

A . 3.3 Mev B. 4.0 Mev

C. 4.5Mev D. 3.0 Mev
59. A man of 100 kg absorbs energy 1000J from radiations for which RBE factor is 10. The equivalent dose will be.

A. 0.01 Sv B. 10000 Sv

C. 100 rem D. 100 Sv
60. When absorbed dose is multiplied with RBE factor then we get

A. dose in joule B. dose in Kg