Work NEET Questions

Physics - Thermodynamics

Work MCQ Questions


13.
For a CYCLIC PROCESS (system returns to initial state), net work done by the system equals:
A.
Zero always
B.
Net heat absorbed (ΔQ_total − ΔQ_rejected) since ΔU = 0 for complete cycle
C.
Sum of all individual work values squared
D.
Total change in internal energy
😑 View Answer Rough Work Error
ANSWER :
B. Net heat absorbed (ΔQ_total − ΔQ_rejected) since ΔU = 0 for complete cycle
14.
In a FREE EXPANSION of gas into vacuum (NCERT Exercise 11.6), work done BY the gas is:
A.
W = −PΔV (surroundings do work)
B.
W = μRΔT
C.
W = 0 — no opposing pressure means no work done despite volume increase
D.
W = PΔV = positive (gas expands)
😑 View Answer Rough Work Error
ANSWER :
C. W = 0 — no opposing pressure means no work done despite volume increase
15.
In the isothermal COMPRESSION of an ideal gas (V₂ < V₁), work done BY the gas W = μRT ln(V₂/V₁) is:
A.
Negative — work is done ON the gas by the surroundings
B.
Equal to internal energy change
C.
Zero — isothermal means no work
D.
Positive — gas does work during compression
😑 View Answer Rough Work Error
ANSWER :
A. Negative — work is done ON the gas by the surroundings
16.
An ideal gas expands adiabatically. As it expands:
A.
Work done by gas is positive; temperature rises because expansion releases heat
B.
Work done is zero; temperature stays constant
C.
Work done by gas is positive; temperature falls because ΔU = −ΔW < 0 (no heat input)
D.
Work done by gas is negative; temperature rises
😑 View Answer Rough Work Error
ANSWER :
C. Work done by gas is positive; temperature falls because ΔU = −ΔW < 0 (no heat input)
17.
For an adiabatic process, a 3 mole sample of monatomic ideal gas (γ = 5/3) cools from 400 K to 300 K. Work done BY the gas is: (R = 8.3 J/mol·K)
A.
2490 J
B.
−3735 J
C.
3735 J
D.
−2490 J
😑 View Answer Rough Work Error
ANSWER :
A. 2490 J
18.
For the CARNOT CYCLE, work done by gas in step 1→2 (isothermal expansion at T₁) is:
A.
W₁₂ = μRT₂ ln(V₂/V₁)
B.
W₁₂ = 0
C.
W₁₂ = μR(T₁−T₂)/(γ−1)
D.
W₁₂ = Q₁ = μRT₁ ln(V₂/V₁)
😑 View Answer Rough Work Error
ANSWER :
D. W₁₂ = Q₁ = μRT₁ ln(V₂/V₁)