Exams › NEET › Physics

Change in entropy is given by ΔS = dQ/T = ΔQ/T = mLf/T.

1. ΔS = 1000 × 80/273
2. ΔS = 293 cal/K
3. Since efficiency of engine is η = 1 − T2/T1
4. According to problem, 1/6 = 1 − T2/T1

Correct answer: ΔS = 1000 × 80/273

Solution

The formula ΔS = mLf/T is used to calculate the change in entropy during a phase change, where m is the mass, Lf is the latent heat of fusion, and T is the temperature in Kelvin. Option A correctly applies this formula.

Related NEET Physics questions

• If for a gas \( \frac{\boldsymbol{R}}{\boldsymbol{C}_{\boldsymbol{v}}}=\mathbf{0 . 6 7}, \) then the gas is made up of molecules which are :
• Use of thermometer is based on which law of thermodynamics?
• The total kinetic energy of 1 mole of \( N_{2} \) at \( 27 \mathrm{C} \) will be approximately
• The quantity \( \frac{2 U}{f k T} \) represents (where \( U= \) internal energy of gas
• A cyclic heat engine does \( 50 \mathrm{kJ} \) of work per cycle. If efficiency of engine is \( 75 \% \) the heat rejected per cycle will be:
• Thermistor material is pressed

⚔️ Practice NEET Physics free + battle 1v1 →