+91-8076753736 [email protected]

-->

Thermodynamics

Question

Wired Faculty App

We consider a thermodynamic system. If ΔU represents the increase in its internal energy and W the work done by the system, which of the following statements is true?

ΔU = -W in an adiabatic process

ΔU = W in an isothermal process

ΔU = -W in an isothermal process

ΔU = W in an adiabtic process

Solution

A.

ΔU = -W in an adiabatic process

An isothermal process is a constant temperature process. In this process

T = constant (or) ΔT = 0

∴ΔU = nC_v ΔT = 0

An adiabatic process is defined as one with no heat transfer into or out of a system. Therefore,

Q = 0

From first law of thermodynamics

W = - ΔU

ΔU = -W

Some More Questions From Thermodynamics Chapter

When a system is taken from state i to state f along the path iaf, it is found that Q = 50 cal and W = 20 cal. Along the path’ ibf Q = 36 cal. W along the path ibf is

The work of 146 kJ is performed in order to compress one kilo mole of gas adiabatically and in this process the temperature of the gas increases by 7° C. The gas is

(R = 8.3 J mol⁻¹ K⁻¹ )

Which of the following is incorrect regarding the first law of thermodynamics?

A system goes from A to B via two processes I and II as shown in the figure. If ∆U₁ and ∆U₂ are the changes in internal energies in the processes I and II respectively, the

Which of the following statements is correct for any thermodynamic system?

Mock Test Series

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation