A metre scale is made up of steel and measures correct length at 16°C. What will be the percentage error if this scale is used (a) on a summer day when the temperature is 46°C and (b) on a winter day when the temperature is 6°C ? Coefficient of linear expansion of steel = 1.1 x 10-5/°C.
(a) Length at 16°C = L
L = ? T1 =16°C, T2 = 46°C
= 1.1 × 10–5 × 30 × 100% = 0.033%
= – 1.1 × 10–5 × 10 × 100 = – 0.011%
