Multiple Choice QuestionsHydrogen atom in ground state is excited by a monochromatic radiation of 
. The number of spectral lines in the resulting spectrum emitted will be,
3
2
6
6
The binding energy per nucleon of 
nuclei are 5.60 MeV and 7.06 MeV, respectively. In the nuclear reaction, 
, the value of energy Q released is,
19.6 MeV
-2.4 MeV
8.4 MeV
8.4 MeV
A radio isotope X with a half life 1.4 x 109 yr decays of Y which is stable. A sample of the rock from a cave was found to contain X and Y in the ratio 1:7. The age of the rock is,
1.96 x 109 yr
3.92 x 109 yr
4.20 x 109 yr
4.20 x 109 yr
C.
4.20 x 109 yr
Ratio of X:Y is given = 1:7
That is,
Let, the initial total mass is m.
Therefore, time taken to become 1/8 unstable part
= 3 x T1/2
= 3 x 1.4 x 109
= 4.2 x 109 y
The given graph represents V-I characteristic for a semiconductor device. Which of the following statement is correct?
It is V-I characteristic for solar cell where point A represents open circuit voltage and point B short circuit current.
It is for a solar cell and points A and B represent open circuit voltage and current, respectively.
It is for a photodiode and points A and B represent open circuit voltage and current, respectively.
It is for a photodiode and points A and B represent open circuit voltage and current, respectively.
The barrier potential of a p-n junction diode depends on:
i) type of semiconductor material
ii) amount of doping
iii) temperature
Which one of the following is correct?
(i) and (ii) only
(ii) only
(ii) and (iii) only
(ii) and (iii) only
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