CBSE
Multiple Choice QuestionsIf 82U238 emits 8 - particles and 6 β - particles, then the resulting nucleus is
82U206
82Pb206
82U210
82U214
The half-life of a radio-isotope is 4h. If initial mass of the isotope was 200 g, then mass remaining after 24 h will be
1.042 g
2.084 g
3.125 g
4.167 g
The operation of a nuclear reactor is said to be critical, if the multiplication factor (k) has a value
1
1.5
2.1
2.5
If r1 and r2 are the radii of the atomic nuclei of mass numbers 64 and 125 respectively, then the ratio ( r1/ r2 ) is
Activity of a radioactive sample decreases to (1/3)rd of its original value in 3 days. Then, in 9 days its activity will become
(1/27) of the original value
(1/9) of the original value
(1/18) of the original value
(1/3) of the original value
the ionization energy of Li2+ is equal to
9hcR
6hcR
2hcR
hcR
Half-lives of two radioactive substances A and B are respectively 20 min and 40 min. Initially the samples of A and B have equal number of nuclei. After 80 min the ratio of remaining number of A and B nuclei is
1 : 16
4 : 1
1 : 4
1 : 1
Hydrogen bomb is based upon
fission
fusion
chemical reaction
transmutation
The specific charge of a proton is 9.6 x 107 C/kg. The specific charge of an alpha particle will be
9.6 x107 C/kg
19.2 x 107 C/kg
4.8 x107 C/kg
2.4 x 107 C/kg
If Mo 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
( Mo - 8 MP ) c2
( Mo - 8 MP - 9 Mc ) c2
Mo C2
(Mo - 17 Mn ) c2
