The resistances of a platinum resistance thermometer at the ice point, the steam point and the boiling point of sulphur are `2.50, 3.50 and 6.50 Omega` respectively. Find the boiling point of sulphur on the platinum scale. The ice point and the steam point measure `0^0 and 100^0` respectively.

Explanation

The temperature on the platinum scale is defined as
`t = (R_t - R_0)/(R_100 - R_0) xx 100^0`,
The boiling point of sulphur on this scale is
`t = (6.50 - 2.50)/(3.50 - 2.50) xx 100^0 = 400^0`.