In which of the following device is the expansion of solid not required?

I. Simple pendulum
II. Fire alarms
III. Thermostat
IV. Bimetallic thermometer

A.

III only

B.

II & III only

C.

I only

D.

II, III & IV only

Correct answer is C

Simple pendulum does not depend on thermal expansion

Five alarms, Thermostat and Bimetallic thermometer are application of thermal expansion of solid

There is an explanation video available below.