The count rate of a Geiger Muller counter for the radiation of radioactive material of half – life 30 min decreases to 5 s-1 after 2 h. Calculate the initial count rate ?
20 s-1
25s-1
80s-1
625s-1
The half-life of a radioactive material is 3 h. If the initial amount is 300g, then after 18 h, it will remain.
4.68g
46.8 g
9.375 g
93. 75 g
Half-life of a radioactive substance is 12.5 h and its mass is 256g. After what time, the amount of remaining substance is 1 g?
75h
100h
125 h
150 h
If an a nuclear fusion process, the masses of the fusing nucle be m1 and m2 and the mass of the resultant nucleus be m3, then :
m3 = m1 + m2
m3 = | m1 - m2|
m3 < (m1 + m2)
m3 > (m1 + m2)
Curie is a unit of
Energy of gamma rays
Half - life
Radioactivity
Intensity of gamma rays
Which of the following statements is true for nuclear forces?
They obey the inverse square law of distance.
They obey the inverse third power law of distance
They are short range forces
They are equal in strength to electromagnetic forces.
Energy released in the fission of a single 92U235 nucleus is 200 MeV. The fission rate of a 92U235 filled reactor operating at a power level of 5 W is.
1.56 × 10-10 s-1
1.56 × 10-11 s-1
1.56 × 10-16 s-1
1.56 × 10-17 s-1
In radioactive decay process, the negatively charged emitted β-particles are.
the electrons present inside the nucleus
the electrons produced as a result of the decay of neutrons inside the nucleus
the electrons produced as a result of collisions between atoms
the electrons orbiting around the nucleus
The fission nuclei is possible because the binding energy per nucleon in them.
increases with mass number at high mass numbers
decreases with mass number at high mass numbers
increases with mass number at low mass numbers
decreases with mass number at low mass numbers
Consider the reaction , if the binding energies of and are respectively α, b and c (in MeV). then the energy (in MeV) released in this reaciton is:
C + a - b
c - a - b
a + b + c
a + b - c
