Physics Electromagnetism MDCAT 2018
PMDC Verified Question 45 of 58
A neutron having mass equal to a proton (\( m_p = 1.6 \times 10^{-27} \ \text{kg} \)) is moving in a magnetic field of intensity \( 1.20 \times 10^{-3} \ \text{T} \) with a speed of \( 2.0 \times 10^7 \ \text{ms}^{-1} \) what is the Maximum force experienced by the neutron.
A
\( 3.84 \times 10^{-15} \ \text{N} \)
B
\( 0 \ \text{N} \)
C
\( 3.84 \times 10^{12} \ \text{N} \)
D
\( 38.4 \times 10^{-15} \ \text{N} \)
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: \( 0 \ \text{N} \)
Concept:

The magnetic force acting on a particle depends fundamentally on the electric charge of that particle. Neutral particles do not interact with magnetic fields in this manner.

Formula:

$$ F = qvB \sin(\theta) $$

Solution:

  • Identify the particle: A neutron.


  • Recall the charge of a neutron: \( q = 0 \ \text{C} \).


  • Substitute this into the Lorentz force equation: \( F = (0) \cdot vB \sin(\theta) \).


  • Therefore, regardless of velocity or magnetic field strength, the magnetic force is exactly 0 N.


Why other options are incorrect:

Options A, C, and D are calculated by falsely assuming the neutron has the charge of a proton (\( 1.6 \times 10^{-19} \ \text{C} \)) and running the numbers.

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 Electromagnetism 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