Advertisements
Advertisements
प्रश्न
A system can be taken from the initial state p1, V1 to the final state p2, V2 by two different methods. Let ∆Q and ∆W represent the heat given to the system and the work done by the system. Which of the following must be the same in both the methods?
पर्याय
∆Q
∆W
∆Q + ∆W
∆Q − ∆W
उत्तर
∆Q − ∆W
A system is taken from an initial state to the final state by two different methods. So, work done and heat supplied in both the cases will be different as they depend on the path followed. On the other hand, internal energy of the system (U) is a state function, i.e. it only depends on the final and initial state of the process. They are the same in the above two methods.
Using the first law of thermodynamics, we get
∆Q = ∆U - ∆W
⇒ ∆U = ∆Q - ∆W
Here, ∆U is the change in internal energy, ∆Q is the heat given to the system and ∆W is the work done by the system.
APPEARS IN
संबंधित प्रश्न
Write the mathematical expression of the First Law of Thermodynamics for Isothermal Process
Calculate the change in internal energy of a gas kept in a rigid container when 100 J of heat is supplied to it.
The pressure of a gas changes linearly with volume from 10 kPa, 200 cc to 50 kPa, 50 cc. (a) Calculate the work done by the gas. (b) If no heat is supplied or extracted from the gas, what is the change in the internal energy of the gas?
When a system is taken through the process abc shown in figure, 80 J of heat is absorbed by the system and 30 J of work is done by it. If the system does 10 J of work during the process adc, how much heat flows into it during the process?
Figure shows the variation in the internal energy U with the volume V of 2.0 mol of an ideal gas in a cyclic process abcda. The temperatures of the gas at b and c are 500 K and 300 K respectively. Calculate the heat absorbed by the gas during the process.
Calculate the increase in the internal energy of 10 g of water when it is heated from 0°C to 100°C and converted into steam at 100 kPa. The density of steam = 0.6 kg m−3. Specific heat capacity of water = 4200 J kg−1 °C−1 and the latent heat of vaporization of water = 2.25 × 10 6J kg−1.
Choose the correct option.
Which of the following is an example of the first law of thermodynamics?
A mixture of hydrogen and oxygen is enclosed in a rigid insulating cylinder. It is ignited by a spark. The temperature and pressure both increase considerably. Assume that the energy supplied by the spark is negligible, what conclusions may be drawn by application of the first law of thermodynamics?
A gas performs 0.320 kJ work on surrounding and absorbs 120 J of heat from the surrounding. Hence, change in internal energy is ______.
Based on first law of thermodynamics which of the following is correct.
Calculate the amount of work done during isothermal expansion of a gas from a volume of 4 dm3 to 6 dm3 against a constant external pressure of 3 atmosphere?
Three copper blocks of masses M1, M2 and M3 kg respectively are brought into thermal contact till they reach equilibrium. Before contact, they were at T1, T2, T3 (T1 > T2 > T3). Assuming there is no heat loss to the surroundings, the equilibrium temprature T is (s is specific heat of copper)
An electric appliance supplies 6000 J/min heat to the system. If the system delivers a power of 90 W. How long it would take to increase the internal energy by 2.5 × 103 J?
Derive an expression for the work done during an isothermal process.
If the adiabatic ratio for a gas is 5/3, find the molar specific heat capacity of the gas at (i) constant volume (ii) constant pressure.
A monoatomic gas at 27°C is adiabatically compressed to 80% of its initial volume. Find the final temperature of the gas.
Choose the correct relation with reason.
Obtain an expression for the workdone by a gas in an isothermal process.
