Question

An invar tape, 30 m in length, standardized at 15°C temperature and 10 kg pull, is used to measure a base line. The correction per tape length, if at the time of measurement, the temperature was 25°C and the coefficient of linear expansion of the tape was $1\times {10}^{-6}pe{r}^{\circ }C$, will be

• A. 0.0003 m
• B. 0.00003 m
• C. 0.003 m
• D. 0.03 m

Answer 1

The correct option is A 0.0003 m

Correction for temperature is,
$C_1=\alpha (T_m-T_0)L$

$where\alpha =\text{coefficient of thermal expansion}$

$T_m=\text{mean temperature in the field during measurement}$

$T_0=\text{standard temperature for the tape}$

L = measured length

$C_1=1\times {10}^{-6}\times (25-15)\times 30$

= 0.0003 m