Question

The coefficient of cubical expansion of a liquid is 9 x 10-5/°C. It's value in ºK is
(A) 4 x 10-5/
(B) 9 x 10-57K
(C) 2 x 10-5/
(D) 5 x 10-57K​

Answer 1

The coefficient of cubical expansion of a liquid is 9 × 10^-5/°C. its value in K is ....

(A) 4 × 10^-5/K

(B) 9 × 10^-5/K

(C) 2 × 10^-5/K

(D) 5 × 10^-5/K

solution : we know, change in volume to raise the temperature from T to T + ∆T is given by,

∆V = Vγ∆T

here γ is coefficient of cubical expansion and ∆T is change in temperature.

here it is clear that

unit of coefficient of cubical expansion depends on change in temperature instead of temperature.

here you should understand that,

change in temperature in °C = change in temperature in K

[ because both are the scale which have 100 equal divisions ]

so the coefficient of cubical expansion in °C = the coefficient of cubical expansion in K

Therefore the coefficient of cubical expansion of the liquid in Kelvin scale is 9 × 10^-5/K

option (B) is correct choice.