70 calories of heat are required to raise the temperature of 2 moles of an ideal gas at constant pressure from `30^(@)` to `35^(@)`. The amount of heat required in calories to raise the temperature of the same gas through the same range `(30^(@)C" to "35^(@)C)` at constant volume is :

Options

A. 70
B. 60
C. 50
D. 35

Answer

C

Explanation

Here `(C_(p))/(C_(v))=1.4`
Now `nC_(p) xx Delta T=70,`
`nxxC_(v)xxDelta T =Q`
`therefore (Q)/(70)=(C_(p))/(C_(v))=(10)/(14)" or "Q=(70xx10)/(14) =50` cals.
`therefore` Correct choice is (c ).