921. In the nucleus of uranium, the number of neutrons will be
A. 92
B. 235
C. 143
D. Different for different isotopes
922. During fusion of hydrogen into helium
A. Energy is absorbed
B. Energy is released
C. Mass is increased due to energy absorption
D. Mass is reduced due to the energy released
923. One AMU is equal to
A. 1.66 x 10-27kg
B. 166 x 10-15ng
C. 166 x 10-20g
D. All of above
924. According to which one of following law the density of atom is uniform?
A. J.J.Thomson model
B. Rutherfords model
C. Bohrs model
D. All of the above laws contradict the statement
925. For chain reaction to build up the size of the radioactive target should be
A. Greater than the critical size
B. Less than the critical size
C. Equal to the critical size
D. All of above can build up a change reaction
926. Antimatter consists of
A. Antiproton
B. Antineutron
C. Positron
D. All of above
927. Neutron and proton are commonly known as
A. Nucleon
B. Meson
C. Boson
D. Quartz
928. The half-life of radium is 1590 years. In how many years shall the earth loss all its radium due to radioactive decay?
A. 1590×106 years
B. 1590×1012 years
C. 1590×1024 years
D. Never
929. Which one of the following radiation possesses maximum penetrating power?
A. X-rays
B. B-rays
C. γ-rays
D. All have the equal penetrating power
930. Electrons
A. Can exist inside the nucleus
B. Cannot exist inside the nucleus
C. Can exist both inside and outside the nucleus
D. Do not know