It is required to prepare a steel metre scale such that the millimetre intervals are to be accurate within 0.0005 mm at a certain temperature. Maximum temperature variation
allowable during the rulings of millimetre marks is :
$({\mathrm{\alpha }}_{\mathrm{steel}}=13.22\times {10}^{-6}/{}^{\mathrm{o}}\mathrm{C})$

• A

  37.8°C

• B

  45.4°C

• C

  10.2°C

• D

  62.6°C