CBSE
Multiple Choice QuestionsAn atom of mass number 15 and atomic number 7 captures an a-particle and then emits a proton. The mass number and atomic number of the resulting atom will be respectively
14 and 12
15 and 3
16 and 4
18 and 8
Mutual inductance of two coils can be increased by
decreasing the number of turns in the coils
increasing the number of turns in the coils
winding the coils on wooden cores
None of these
Assertion: The ratio for time taken for light emission from an atom to that for release of nuclear energy in fission is 1 : 100.
Reason: Time taken for the light emission from an atom is of the order of 10-8 s.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
A neutron in a nuclear reactor collides head on elastically with the nucleus of a carbon atom initially at rest. The fraction of kinetic energy transferred from the neutron to the carbon atom is
Assertion: If a heavy nucleus is split into two medium-sized parts, each of the nuclei will have more binding energy per nucleon than the original nucleus.
Reason: Joining two light nuclei together to give a single nucleus of medium size means more binding energy per nucleon than the two nucleus.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false.
If both assertion and reason are false.
The half-life of radium is 1600 years. What is the fraction of sample undecayed after 6400 years?
Assertion: Thermonuclear fusion reactions may become the source of unlimited power for the mankind.
Reason: A single fusion event involving isotopes of hydrogen produces more energy from nuclear fission of
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
n-alpha particles per second are emitted from N atoms of a radioactive element. The half-life of the radioactive element is
Assertion: Generally heavy nuclei are unstable.
Reason: It has more neutrons and protons.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false
A zener diode is specified as having a breakdown voltage of 9.1 V, with a maximum power dissipation of 364 mW. What is the maximum current the diode can handle?
40 mA
60 mA
50 mA
45 mA
