Question

When the shaft is not transmitting torque, which of the following phenomenon occurs?

(a) Visible Flashing of light

(b) Flashing of light cannot be seen

(c) Angle of torsion cannot be measured

(d) Torsion meter stops working

This question was addressed to me by my college professor while I was bunking the class.

The origin of the question is Bevis Gibson Flash Light Torsion Dynamometer in division Brakes and Dynamometers of Machine Dynamics

Answer 1

The correct option is (a) Visible Flashing of light

Easy explanation: When the shaft is not transmitting torque, the position of slit does not change relative to one another, as a result flashing of light can be seen. This phenomenon occurs only because the relative position of slits does not change.