Two radioactive materials X1 and X2 have decay constant 5 λ res

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

141.

The activity of a radioactive sample is measured as No counts per minute at t = 0 and No/e counts per minute at t = 5 min. The time (in minute) at which the activity reduces to half its value is

  • loge 2 /5

  • 5/ loge 2

  • 5 log10 2

  • 5 log10 2

579 Views

142.

The decay constant of a ratio isotope is λ. If A1 and A2 are its activities at times t1 and t2 respectively, te number of nuclei which have decayed during the time (t1-t2)

  • A1t1 - A2t2

  • A1 - A2

  • (A1 - A2)/λ

  • (A1 - A2)/λ

490 Views

143.

The binding energy per nucleon in deuterium and helium nuclei are 1.1 MeV and 7.0 MeV, respectively. When two deuterium nuclei fuse to form a helium nucleus the energy released in the fusion is

  • 23.6 MeV

  • 2.2 MeV

  • 28.0 MeV

  • 28.0 MeV

596 Views

144.

In the nuclear decay given below,

straight X presubscript straight Z presuperscript straight A space rightwards arrow straight Y presubscript straight Z plus 1 end presubscript presuperscript straight A space rightwards arrow space straight B presubscript straight Z minus 1 end presubscript presuperscript straight A minus 4 end presuperscript asterisk times space rightwards arrow space straight B presubscript straight Z minus 1 end presubscript presuperscript straight A minus 4 end presuperscript
the particle emitted in the sequence are

  • β, α, γ

  • γ, β, α, 

  •  β,γ, α

  •  β,γ, α

339 Views

Advertisement
145.

The number of beta particles emitted by radioactive substance is twice the number  of alpha particle emitted by it. The resulting daughter is an 

  • isobar of parent

  • isomer of parent

  • isotone of parent

  • isotone of parent

584 Views

Advertisement

146.

Two radioactive materials X1 and X2 have decay constant 5 λ respectively. If initially, they have the same number of nuclei, then the ratio of the number of nuclei of X1 to that of X2 will be 1/e after a time

  • λ

  • λ/2

  • 1/4λ

  • 1/4λ


C.

1/4λ

If N is the number of radioactive nuclei present at some instant then



1681 Views

Advertisement
147.

If M (A, Z), MP and Mn denote the masses of the nucleus straight X presubscript straight Z presuperscript straight A  proton and neutron respectively in units of u (1 u = 931.5 MeV/c2) and BE represents its binding energy  in MeV, then


  • M (A,Z) = ZMp + (A-Z)Mn - BE/c2

  • M (A,Z) = ZMp + (A-Z)Mn + BE

  • M (A,Z) = ZMp + (A-Z)Mn - BF

  • M (A,Z) = ZMp + (A-Z)Mn - BF

383 Views

148.

Two nuclei have their mass number in the ratio of 1:3. The ratio of their nuclear densities would be

  • 1:3

  • 3:1

  • (3)1/3 : 1

  • (3)1/3 : 1

382 Views

Advertisement
149.

In radioactive decay process, the negatively charged emitted beta 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 produced as a result of collisions between atoms

424 Views

150.

A nucleus has straight X presubscript straight Z presuperscript straight A mass represented by  M (A, Z). If Mp and Mn denote the mass of proton and neutron respectively and BE the binding energy (in MeV), then:

  • BE = [M(A,Z)-ZMp - (A-Z)Mn]c2

  • BE = [ZMp + (A-Z)Mn -M(A,Z)]c2

  • BE = [ZMp + AMn - M (A,Z)]c2

  • BE = [ZMp + AMn - M (A,Z)]c2

526 Views

Advertisement