Physics Rotational & Circular Motion BUMHS 2022
PMDC Verified Question 59 of 95
The ratio of angular speed of a minute hand to hour hand of the watch is?
A
1:6
B
6:1
C
1:12
D
12:1
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: 12:1
Concept:

Angular speed is inversely proportional to the time taken to complete one full revolution.

Formula:

$$ \omega = \frac{2\pi}{T} $$

Solution:

  • The minute hand completes a full revolution every 1 hour. So, \( T_m = 1 \text{ hr} \).
  • The hour hand completes a full revolution every 12 hours. So, \( T_h = 12 \text{ hrs} \).
  • Their speeds are \( \omega_m = \frac{2\pi}{1} \) and \( \omega_h = \frac{2\pi}{12} \).
  • Taking the ratio: \( \frac{\omega_m}{\omega_h} = \frac{2\pi/1}{2\pi/12} = \frac{1}{1/12} = 12 \).
  • Therefore, the ratio is \( 12:1 \).


Why other options are incorrect:

  • Option C is flipped (hour hand to minute hand).
  • Option A and Option B use mathematically flawed time conversions.

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 Rotational & Circular Motion 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