A uniform metallic object of circular shape which is free to expand in every direction is shown in figure. The parameter which will not increase on hearing the object is:

Options

A. x(gap)
B. r(radius of circle)
C. `theta`(angle formed at centre)
D. t(thickness)

Answer

C

Explanation

`theta=x/r rArr theta'=(x+Deltax)/(R+DeltaR)=(x(1+alphaDeltaT))/(R(1+alphaDeltaT))=x/R`
So, `theta` will remains constant rest all will increases.