Physics-
General
Easy
Question
The number of revolutions per second made by an electron in the first Bohr orbit of hydrogen atom is of the order of3
The correct answer is:
(for first orbit)
Related Questions to study
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In a radioactive reaction 
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In a radioactive reaction , the number of particles emitted is
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Activity of radioactive element decreased to one third of original activity 
in 9 years. After further 9 years, its activity will be
Activity of radioactive element decreased to one third of original activity in 9 years. After further 9 years, its activity will be
Physics-General
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Which of the following rays are not electromagnetic waves
Which of the following rays are not electromagnetic waves
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The ratio activity of an element becomes 1/64th of its original value in 60 sec. Then the half life period is
The ratio activity of an element becomes 1/64th of its original value in 60 sec. Then the half life period is
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In the disintegration series
The value of Z and A respectively will be
In the disintegration series
The value of Z and A respectively will be
Physics-General
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A radioactive nucleus with Z protons and N neutrons emits an 
-particle, 2 
-particles and 2 gamma rays. The number of protons and neutrons in the nucleus left after the decay respectively, are
A radioactive nucleus with Z protons and N neutrons emits an -particle, 2 -particles and 2 gamma rays. The number of protons and neutrons in the nucleus left after the decay respectively, are
Physics-General
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What fraction of a radioactive material will get disintegrated in a period of two half-lives
What fraction of a radioactive material will get disintegrated in a period of two half-lives
Physics-General
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An atomic nucleus 
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An atomic nucleus emits several and radiations and finally reduces to . It must have emitted
Physics-General
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At any instant the ratio of the amount of radioactive substances is 2 : 1. If their half lives be respectively 12 and 16 hours, then after two days, what will be the ratio of the substances
At any instant the ratio of the amount of radioactive substances is 2 : 1. If their half lives be respectively 12 and 16 hours, then after two days, what will be the ratio of the substances
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Radiocarbon dating is done by estimating in specimen the
Radiocarbon dating is done by estimating in specimen the
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If the decay constant of a radioactive substance is 
, then its half-life is
If the decay constant of a radioactive substance is , then its half-life is
Physics-General
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Which one of the following statement is true, if half-life of a radioactive substance is 1 month?
Which one of the following statement is true, if half-life of a radioactive substance is 1 month?
Physics-General
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Two nuclei have their mass numbers in the ratio of 1:3. The ratio of their nuclear densities would be
Two nuclei have their mass numbers in the ratio of 1:3. The ratio of their nuclear densities would be
Physics-General
Physics-
The above is a plot of binding energy per nucleon 
against the nuclear mass 
correspond to different nuclei. Consider four reactions 
where 
is the energy released? In which reaction is positive?
The above is a plot of binding energy per nucleon against the nuclear mass correspond to different nuclei. Consider four reactions where is the energy released? In which reaction is positive?
Physics-General
Chemistry-
Fe(OH)3 can be separated from Al(OH)3 by addition of
Fe(OH)3 can be separated from Al(OH)3 by addition of
Chemistry-General
