Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
MHT CET Medical202624 April 2026Evening ShiftPhysicsThermodynamicsActual

Which of the following statements is NOT CORRECT? In an isothermal process, a. there is perfect thermal equilibrium with environment. b. there is no change in internal energy during the process. c. the work done is equal to zero. d. the time taken is very large.

Options

  1. Ac
  2. Ba
  3. Cd
  4. Db

Correct answer

A. c

Step-by-step solution

In an isothermal process, the temperature of the system remains constant, which means T = 0 . For an ideal gas, the internal energy depends only on temperature, so the change in internal energy U = 0 . To maintain a constant temperature, the process must be carried out very slowly so that the system remains in perfect thermal equilibrium with its surroundings. Thus, the time taken for the process is very large. According to the first law of thermodynamics, Q = U + W . Since U = 0 , we have Q = W . The work done in

Practice Thermodynamics on Quantrex Academy →

More from Thermodynamics

The work done by an ideal gas during closed cycle 1 2 3 4 1 as shown in figure is 2026Let ₁ be the efficiency of a Carnot engine at T_H = 547^ C and T_C = 247^ C while ₂ is the efficiency at T_H = 847^ C and T_C = 147^ C . If ₁ = x 41 ₂ , the value of x is 2026Identify the INCORRECT statement for isobaric process. 2026A gas for which = 5 / 3 ( = C_p / C_v ) is heated at constant pressure. The percentage of heat supplied used for external work is 2026A mono-atomic ideal gas, initially at temperature T₁ is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature T₂ by 2026A gas for which is 3/2 is heated at constant pressure. The percentage of heat supplied for external work is nearly 2026One mole of an ideal gas in initial state A undergoes a cyclic process ABCA, as shown in the figure. Its pressure at A is P₀ . Choose the correct option from the following. 2026An ideal mono-atomic gas is heated at constant pressure. The fraction of the total energy applied which increases the internal energy for the gas is 2026 Full Thermodynamics list All MHT CET Medical PYQs