Question

A brass scale gives correct length at $0^{\circ }C$. If the temperature be ${25}^{\circ }C$ and the length read by the scale is 10 cm. Then the actual length will be :

• A. more than 10 cm
• B. less than 10 cm
• C. equal to 10 cm
• D. we can not say

Answer 1

The correct option is A more than 10 cm

AS temperature increase length of scale will increase due to expansion and given by expression-

$L=\left(actuallengthat0℃\right)(1+T\times \alpha )$

but mark on scale will remain on same location. Now if scale measure 10 cm length and scale itself expanded due to temperature increase then object is larger than 10cm.