NEET-UG and JEE Main Physics · Class 12
Radioactivity - alpha, beta and gamma rays; the decay law — NEET & JEE Questions
Radioactivity - alpha, beta and gamma rays; the decay law is a topic in Atoms and Nuclei, a Class 12 Physics chapter of the NEET-UG and JEE Main syllabus. TestBudy holds 14 published NEET-UG and JEE Main questions on Radioactivity - alpha, beta and gamma rays; the decay law, each with the marking scheme of the real paper.
- questions
- 14
- shown here
- 10
Five free tests with an account. Your score comes with the result; where you stand is Pro.
Radioactivity - alpha, beta and gamma rays; the decay law MCQs with solutions
10 of the 14 published questions on this topic, exactly as they appear in a test. Answers and worked solutions come with your result rather than on this page.
Alpha radiation consists of
- A. electrons only
- B. high-energy photons
- C. helium nuclei
- D. neutrons only
Beta-minus decay emits
- A. a helium nucleus
- B. a gamma photon only
- C. a proton as the beta particle
- D. an electron along with an antineutrino in the full process
Gamma radiation consists of
- A. high-energy electromagnetic photons
- B. helium nuclei
- C. electrons only
- D. protons only
Radioactive decay law is
- A. N=N0(1+λt)
- B. N=N0 e^(-λt)
- C. N=N0 e^(+λt)
- D. N=λt only
Which radioactive emission has the greatest penetrating power among alpha, beta and gamma radiations?
- A. Alpha
- B. Beta
- C. Gamma
- D. All have identical penetrating power
Half-life is related to decay constant by
- A. T1/2=λ ln2
- B. T1/2=1/(2λ)
- C. T1/2=ln2/λ
- D. T1/2=λ
After three half-lives, the undecayed fraction is
- A. 1/3
- B. 1/6
- C. 1/9
- D. 1/8
A radioactive nucleus emits an alpha particle. How do its mass number A and atomic number Z change?
- A. A decreases by 4 and Z by 2
- B. A decreases by 2 and Z by 4
- C. A is unchanged and Z decreases by 1
- D. A and Z are both unchanged
A radioactive sample has half-life 3 hours. What fraction of the original nuclei remains after 9 hours?
- A. 1/2
- B. 1/4
- C. 1/8
- D. 1/16
Activity A of a radioactive sample is
- A. A=λN
- B. A=N/λ
- C. A=λ/N
- D. A=N0-N only
Common mistakes in Radioactivity - alpha, beta and gamma rays; the decay law
Recorded against questions in this topic that are not shown above, so none of these points at an answer you can see on this page.
- Subtracts a fixed number of nuclei each half-life instead of using exponential decay.
Practise this chapter
Reading a question and answering it under a clock are different things. A chapter-length test measures whether the topic went in.