If the nucleus has a nuclear radius of about 3.6 fm, then would have its radius approximately as:
6.0 fm
9.6 fm
12.0 fm
12.0 fm
Two radioactive substance A and B have decay constants 5λ and λ respectively. At t = 0 they have the same number of nuclei. The ratio of a number of nuclei of A to those of B will be after a time interval:
1/ 4λ
4λ
2λ
1/2λ
Monochromatic light of frequency 6.0 x 1014 Hz is produced by a laser. The power emitted is 2 x 10-3 W The number of photons emitted, on the average, by the source per second is:
5 x 1015
5 x 106
5 x 1017
5 x 1017
The binding energy of deuteron is 2.2 MeV and that of is 28 MeV. If two deuterons are fused to form one then the energy released is
25.8 MeV
23.6 MeV
19.2 MeV
19.2 MeV
In a radioactive material the activity at time t1 is R1 and at a later time t2, it is R2. If the dacay constant of the material is λ, then
R1 = R2 e-λ(t1 -t2 )
R1 = R2 eλ(t1 -t2 )
R1 = R2 e(t2 /t1 )
R1 = R2 e(t2 /t1 )
The radius of germanium (Ge) nuclide is measured to be twice the radius of The number of nucleons in Ge are
73
74
75
75
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
1/8λ
For a radioactive material, the half-life is 10 minutes. If initially there are 600 number of nuclei, the time is taken (in minutes) for the disintegration of 450 nuclei is
20
10
15
30
When the radioactive isotope decays in a series by the emission of three alpha (α) and a beta (β) particle, the isotope X which remains undecay is
N lamps each of resistance r, are fed by the machine of resistance R. If light emitted by any lamp is proportional to the square of the heat produced, prove that the most efficient way of arranging them is to place them in parallel arcs, each containing n lamps, where n is the integer nearest to.
(NRr)3/2
(NRr)1/2