# What is the principle of torsional pendulum?

## What is the principle of torsional pendulum?

A torsion pendulum or torsional oscillator consista of a disk-like mass suspended from thin rod. When the mass is twisted about the axis of the wire , the wire exerts a torque on the mass, tending to rotate it back to its original position.

## Why torsional pendulum is called so?

noun Horology. a pendulum the weight of which is rotated alternately in opposite directions through a horizontal plane by the torsion of the suspending rod or spring: used for clocks intended to run a long time between windings.

What type of motion in torsion pendulum observe?

Similar to the simple pendulum, so long as the angular displacement is small (which means the motion is SHM) the period is independent of the displacement. Torsional pendulums are also used as a time keeping devices , as in for example, the mechanical wristwatch .

### What is the unit of torsional pendulum?

in which a torque τ causes one end of a rod to rotate through an angle θ, measured in radians, while the other end of the rod is fixed. The torsion constant has units of N-m/rad in the SI system.

### What is the time period of torsional pendulum?

The period of a torsional pendulum T=2π√Iκ T = 2 π I κ can be found if the moment of inertia and torsion constant are known.

What is angle of twist in torsional pendulum?

The work required to twist a wire through an angle θ is 12cθ2. When a torsion pendulum is oscillating, its Equation of motion is. I¨θ=−cθ. This is an Equation of the form 11.1. 5 and is therefore simple harmonic motion in which ω=√cI.

#### What is the angular frequency of torsional pendulum?

The frequency in cycles per second, ν, equals ω/(2π). The period of oscillation, T, equals (2π)/ω, or 1/ν. φ is a phase factor, which depends on how the motion starts. We see that the frequency at which the torsional pendulum oscillates is proportional to √k, and inversely proportional to √I.

What is the application of torsional pendulum?

Torsion pendulums are often used for time-keeping purposes. For instance, the balance wheel in a mechanical wristwatch is a torsion pendulum in which the restoring torque is provided by a coiled spring.

## What is rigidity modulus in torsional pendulum?

A torsion pendulum is an oscillator for which the restoring force is torsion. Rigidity modulus or shear modulus is the ratio of shear stress to the displacement per unit sample length. When a circular disc is suspended through a wire, it undergoes torsion or coupling effect.

What is moment of inertia in torsional pendulum?

A body’s inherent resistance to rotational acceleration about a specific axis is called its’ mass moment of inertia about that axis.