In radioactive decay process, the negatively charged emitted

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

171.

Fission of nuclei is possible because the binding energy per nucleon in them

  • increases with mass number at high mass numbers

  • decreases with mass number at high mass numbers

  • increases with mass number at low mass numbers 

  • decreases with mass number at low mass numbers


172.

In any fission process the ratio Mass of parent nucleusMass of fission products is

  • less than 1

  • greater than 1

  • greater than 1

  • depends on the mass of parent nucleus


Advertisement

173.

In radioactive decay process, the negatively charged emitted -particles are 

  • the electrons present inside the nucleus

  • the electrons produced as a result of the decay of neutrons inside the nucleus

  • the electrons produced as a result of collisions between atoms

  • the electrons orbiting around the nucleus


B.

the electrons produced as a result of the decay of neutrons inside the nucleus

(1) Beta decay can involve the emission of either electrons or positrons. The electrons or positrons emitted in a β-decay do not exist inside the nucleus. They are only created at the time of emission, just as photons are created when an atom makes a transition from higher to a lower energy state.
(2) In negative β-decay a neutron in the nucleus is transformed into a proton, an electron and an antineutrino. Hence, in radioactive decay process, the negatively charged emitted particles are the electrons produced as a result of the decay of neutrons present inside the nucleus.


Advertisement
174.

Two radioactive substances A and B have decay constants 5 λ and λ respectively. At t = 0 they have the same number of nuclei. The ratio of number of nuclei of A to those of B will be 1e2 after a time interval

  • 14λ

  • 12λ


Advertisement
175.

If Mo is the mass of an oxygen isotope 8O17 , MP and Mn are the masses of a proton and a neutron, respectively, the nuclear binding energy of the isotope is

  • ( Mo - 8 MP ) c2 

  • ( Mo - 8 MP - 9 Mc ) c2

  • Mo C2

  • (Mo - 17 Mn ) c2


176.

Hydrogen bomb is based upon

  • fission

  • fusion

  • chemical reaction

  • transmutation


177.

The operation of a nuclear reactor is said to be critical, if the multiplication factor (k) has a value

  • 1

  • 1.5

  • 2.1

  • 2.5


178.

Half-lives of two radioactive substances A and B are respectively 20 min and 40 min. Initially the samples of A and B have equal number of nuclei. After 80 min the ratio of remaining number of A and B nuclei is

  • 1 : 16

  • 4 : 1

  • 1 : 4

  • 1 : 1


Advertisement
179.

The half-life of a radio-isotope is 4h. If initial mass of the isotope was 200 g, then mass remaining after 24 h will be

  • 1.042 g

  • 2.084 g

  • 3.125 g

  • 4.167 g


180.

If 82U238 emits 8 α - particles and 6 β - particles, then the resulting nucleus is

  • 82U206

  • 82Pb206

  • 82U210

  • 82U214


Advertisement