`5` moles of nitrogen gas are enclosed in an adiabatic cylindrical vessel. Thel piston itself is a rigid light cylindrical container containing `3` moles of helium gas. There is a heater which given out a power of `30` cal is transferred to helium through the batton surface of the piston. The rate of incremnt of temperature of the nitrogen gas assuming that the piston
moves slowly, is

Options

A. `2 K//s`
B. `4 K//s`
C. `6 K//s`
D. `8 K//s`

Answer

A

Explanation

Net power given to `N_(2)` gas `= 100 - 30 = 70` cal/s
The nitrogen gas expands isobarically
`:. Q=nC_(p)(dT)/(dt) or 70=5xx(7)/(2)R(dT)/(dt)`
`:. (dT)/(dt) =2 K//s`