Radioactive material 'A' has a decay constant '8λ' and material 'B' has decay constant 'λ'. Initially, they have a same number of nuclei. After what time, the ratio of a number of nuclei of material 'B' to that 'A' will be 1/e?
1/λ
1/7λ
1/8λ
1/9λ
B.
1/7λ
If M0 is the mass of an oxygen isotope 8O17 , Mp and MN are the masses of a proton and a neutron respectively, the nuclear binding energy of the isotope is
In gamma-ray emission from a nucleus
When 3Li7 nuclei are bombarded by protons, and the resultant nuclei are 4Be8 , the emitted particles will be
The ‘rad’ is the correct unit used to report the measurement of
A photocell is illuminated by a small bright source placed 1 m away. When the same source of light is placed 1 /2 m away, the number of electrons emitted by photocathode would
Mock Test Series
