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प्रश्न
Define an isolated system.
उत्तर
A system that does not allow the exchange of either energy or matter with the surroundings is called an isolated system.
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संबंधित प्रश्न
When we heat an object, it expands. Is work done by the object in this process? Is heat given to the object equal to the increase in its internal energy?
The first law of thermodynamics is a statement of ____________ .
The internal energy of an ideal gas decreases by the same amount as the work done by the system.
(a) The process must be adiabatic.
b) The process must be isothermal.
(c) The process must be isobaric.
(d) The temperature must decrease.
Calculate the change in internal energy of a gas kept in a rigid container when 100 J of heat is supplied to it.
Consider the cyclic process ABCA, shown in figure, performed on a sample of 2.0 mol of an ideal gas. A total of 1200 J of heat is withdrawn from the sample in the process. Find the work done by the gas during the part BC.
Choose the correct option.
Which of the following is an example of the first law of thermodynamics?
A solar cooker and a pressure cooker both are used to cook food. Treating them as thermodynamic systems, discuss the similarities and differences between them.
A resistor held in running water carries electric current. Treat the resistor as the system
- Does heat flow into the resistor?
- Is there a flow of heat into the water?
- Is any work done?
- Assuming the state of resistance to remain unchanged, apply the first law of thermodynamics to this process.
For an Isothermal process
10 kg of four different gases (Cl2, CH4, O2, N2) expand isothermally and reversibly from 20 atm to 10 atm. The order of amount of work will be ____________.
When heat energy of 2000 joules is supplied to a gas at constant pressure 2.1 x 105 N/m2, there is an increase in its volume equal to 2.5 x 10-3 m3. The increase in internal energy of the gas in joules is ____________.
"The mass and energy both are conserved in an isolated system", is the statement of ______.
In a given process for an ideal gas, dW = 0 and dQ < 0. Then for the gas ____________.
For a particular reaction, the system absorbs 8 kJ of heat and does 2.5 kJ of work on its surrounding. What will be the change in internal energy of the system?
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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)
A system goes from P to Q by two different paths in the P-V diagram as shown in figure. Heat given to the system in path 1 is 1000 J. The work done by the system along path 1 is more than path 2 by 100 J. What is the heat exchanged by the system in path 2?
The initial state of a certain gas is (Pi, Vi, Ti). It undergoes expansion till its volume becomes Vf. Consider the following two cases:
- the expansion takes place at constant temperature.
- the expansion takes place at constant pressure.
Plot the P-V diagram for each case. In which of the two cases, is the work done by the gas more?
A cycle followed by an engine (made of one mole of perfect gas in a cylinder with a piston) is shown in figure.
A to B : volume constant
B to C : adiabatic
C to D : volume constant
D to A : adiabatic
VC = VD = 2VA = 2VB
- In which part of the cycle heat is supplied to the engine from outside?
- In which part of the cycle heat is being given to the surrounding by the engine?
- What is the work done by the engine in one cycle? Write your answer in term of PA, PB, VA.
- What is the efficiency of the engine?
(γ = `5/3` for the gas), (Cv = `3/2` R for one mole)
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- What is the initial pressure of the system?
- What is the final pressure of the system?
- Using the first law of thermodynamics, write down a relation between Q, Pa, V, Vo and k.
The first law of thermodynamics is concerned with the conservation of ______.
An ideal gas is taken through series of changes ABCA. The amount of work involved in the cycle is ______.
The first law of thermodynamics for isothermal process is ______.
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An ideal gas having pressure p, volume V and temperature T undergoes a thermodynamic process in which dW = 0 and dQ < 0. Then, for the gas ______.
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Explain the formulation of first law of thrmodynamics.
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Choose the correct relation with reason.
