A metal rod having a coefficient of linear expansion of 2 × 10-5 /°C has a length of 100 cm at 20 °C. The temperature at which it is shortened by 1 mm is
A. -40 °C
B. -30 °C
C. -20 °C
D. -10 °C
Answer:B
A metal rod having a coefficient of linear expansion of 2 × 10-5 /°C has a length of 100 cm at 20 °C. The temperature at which it is shortened by 1 mm is
A. -40 °C B. -30 °C C. -20 °C D. -10 °C