In a simple pendulum, the tension of the string is:

Correct answer: C. T = mg cos θ

  • A. T = g cos θ
  • B. T = mg sin θ
  • C. T = mg cos θ
  • D. T = mg

Explanation

The correct answer is C: T = mg cos θ. In a simple pendulum, the tension in the string must balance the component of the gravitational force that acts perpendicular to the arc of the pendulum's swing, which is mg cos θ. Option A is incorrect because g cos θ alone does not represent the tension; it lacks the mass component. Option B is incorrect because mg sin θ is the component of the force parallel to the swing's direction, not the tension. Option D is incorrect because mg represents the full weight of the pendulum bob, which does not account for the angle of the swing.

This question appeared on the UHS MDCAT 2010 paper, which you can sit online with every answer explained.

Written and checked by , contributorLast updated
Report an error

The more specific you are, the faster it gets fixed. A source beats an opinion.

Prefer email? [email protected]

About Simple Harmonic Motion

Simple harmonic motion is oscillation in which acceleration is directly proportional to displacement and directed toward the equilibrium position. Work includes displacement, velocity, acceleration, phase, period, frequency, amplitude and energy, with applications to springs and simple pendulums. The restoring force and the conditions for SHM distinguish it from general periodic motion.

Practise Waves

1,281 free Waves MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Discussion

Stuck on an option, or know a faster way to get there? Ask or explain it here.

No comments yet. Be the first to explain this one.

Exams that ask Physics questions like this

Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

More Simple Harmonic Motion questions