EASY
Earn 100

Statement: Neptunium is named after the planet Neptune.

State the given statement is true or false.

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Important Questions on Nuclear Physics

EASY
The half-life period of a radioactive element X is same as the mean-life time of another radioactive element Y.
Initially, they have the same number of atoms. Then,
MEDIUM
The activity of a radioactive sample falls from 700s-1 to 500s-1 in 30 minutes. Its half life is close to:
EASY
The end product of decay of 90Th232 is 82Pb208. The number of α and β particles emitted are respectively
MEDIUM
Radioactive element decays to form a stable nuclide, then the rate of decay of reactant is shown by
EASY
A nucleus of uranium decays at rest into nuclei of thorium and helium. Then:
EASY

Activities of three radioactive substances A, B and C are represented by the curves A, B and C, in the figure. Then their half-lives T12A:T12B:T12C are in the ratio:

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EASY

Which one of the following nuclei has shorter mean life?

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HARD
At some instant, a radioactive sample S1 having an activity 5 μCi has twice the number of nuclei as another sample S2 which has an activity of 10 μCi . The ratio of half lives of S1 and S2 is
EASY
A radioactive nucleus A with a half-life T, decays into a nucleus B. At t=0, there is no nucleus B. At some time t, the ratio of the number of B to that of A is 0.3. Then, t is given by: Consider logex=logx
MEDIUM
The half-life period and the mean life period of a radioactive element are denoted respectively by Th and Tm. Then
MEDIUM
At a given instant, say t=0, two radioactive substance A and B have equal activities. The ratio RBRA of their activities after time t itself decays with time t as e-3t. If the half-life of A is ln2, the half-life of B is:
MEDIUM
The activity of a radioactive sample is measured as N0 counts per minute at t=0 and N0e counts per minute at t=5 min. The time (in minutes) at which the activity reduces to half its value is
MEDIUM
In a radioactive material, a fraction of active material remaining after the time t is 916 . The fraction that was remaining after the time t2 is :
MEDIUM
Th90232 emits 6α and 4β particles and gets converted into a lead. The mass number and atomic number of lead is _____
EASY

Assertion (A) : Neutrino is chargeless and possesses spin.

Reason (R):   Neutrino exists inside the nucleus.

EASY
A radio-active element has a half-life of 15 years. What fraction of this element will decay in 30 years?
MEDIUM
Half lives of two radioactive nuclei A and B are 10 minutes and 20 minutes, respectively. If, initially a sample has equal number of nuclei, then after 60 minutes, the ratio of decayed numbers of nuclei A and B will be:
HARD
In a radioactive decay chain,  90232Th nucleus decays to  82212Pb nucleus. Let Nα and Nβ be the number of α and β- particles, respectively, emitted in this decay process. Which of the following statements is (are) true?
HARD
An accident in a nuclear laboratory resulted in deposition of a certain amount of radioactive material of half-life 18 days inside the laboratory. Tests revealed that the radiation was 64 times more than the permissible level required for safe operation of the laboratory. What is the minimum number of days after which the laboratory can be considered safe for use?