Physics Nuclear Physics SZABMU 2023
PMDC Verified Question 21 of 98
The rate of radioactive decay is directly proportional to the stability of the:
A
Medium
B
Atmosphere
C
Isotopes
D
Half life
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option C: Isotopes


Concept:

The fundamental law of radioactive decay connects the decay rate strictly to the properties of the specific unstable atoms.

Formula:

$$ \frac{\Delta N}{\Delta t} = -\lambda N $$

Solution:

  • The formula states that the rate of decay is directly proportional to \(N\), which is the number of active, unstable isotopes currently present in the sample.


  • The rate has absolutely nothing to do with external conditions like atmospheric pressure or surrounding medium.


  • is slightly awkward, but "isotopes" is the only option representing the physical nuclei undergoing decay.


Why other options are incorrect:

Decay is fully independent of macroscopic medium and atmosphere. It is inversely proportional to half-life, not directly proportional.

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

Previous Question All Nuclear Physics MCQs Next Question

Want to solve full-length papers under timed exam conditions?

Practice with zero-scroll lockdown sprints, dynamic latency zone timers, live peer selection telemetry, and the automated Amber mistake recovery loop.

Enter Arena Sprint iOS App Android App