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प्रश्न
Which of the following system freely allows the exchange of energy and matter with its environment?
विकल्प
Closed
Isolated
Open
partially closed
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उत्तर
Open
संबंधित प्रश्न
Explain why Air pressure in a car tyre increases during driving.
Two cylinders A and B of equal capacity are connected to each other via a stopcock. A contains a gas at standard temperature and pressure. B is completely evacuated. The entire system is thermally insulated. The stopcock is suddenly opened. Answer the following:
Do the intermediate states of the system (before settling to the final equilibrium state) lie on its P-V-T surface?
Should the internal energy of a system necessarily increase if its temperature is increased?
Can work be done by a system without changing its volume?
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Refer to figure. Let ∆U1 and ∆U2 be the changes in internal energy of the system in the process A and B. Then _____________ .
Consider two processes on a system as shown in figure.
The volumes in the initial states are the same in the two processes and the volumes in the final states are also the same. Let ∆W1 and ∆W2 be the work done by the system in the processes A and B respectively.
The pressure p and volume V of an ideal gas both increase in a process.
(a) Such a process is not possible.
(b) The work done by the system is positive.
(c) The temperature of the system must increase.
(d) Heat supplied to the gas is equal to the change in internal energy.
In a process on a system, the initial pressure and volume are equal to the final pressure and volume.
(a) The initial temperature must be equal to the final temperature.
(b) The initial internal energy must be equal to the final internal energy.
(c) The net heat given to the system in the process must be zero.
(d) The net work done by the system in the process must be zero.
A 100 kg lock is started with a speed of 2.0 m s−1 on a long, rough belt kept fixed in a horizontal position. The coefficient of kinetic friction between the block and the belt is 0.20. (a) Calculate the change in the internal energy of the block-belt system as the block comes to a stop on the belt. (b) Consider the situation from a frame of reference moving at 2.0 m s−1 along the initial velocity of the block. As seen from this frame, the block is gently put on a moving belt and in due time the block starts moving with the belt at 2.0 m s−1. calculate the increase in the kinetic energy of the block as it stops slipping past the belt. (c) Find the work done in this frame by the external force holding the belt.
Figure shows three paths through which a gas can be taken from the state A to the state B. Calculate the work done by the gas in each of the three paths.
A gas is taken through a cyclic process ABCA as shown in figure. If 2.4 cal of heat is given in the process, what is the value of J ?
A gas is initially at a pressure of 100 kPa and its volume is 2.0 m3. Its pressure is kept constant and the volume is changed from 2.0 m3 to 2.5 m3. Its Volume is now kept constant and the pressure is increased from 100 kPa to 200 kPa. The gas is brought back to its initial state, the pressure varying linearly with its volume. (a) Whether the heat is supplied to or extracted from the gas in the complete cycle? (b) How much heat was supplied or extracted?
When does a system lose energy to its surroundings and its internal energy decreases?
One gram of water (1 cm3) becomes 1671 cm3 of steam at a pressure of 1 atm. The latent heat of vaporization at this pressure is 2256 J/g. Calculate the external work and the increase in internal energy.
A thermodynamic system goes from states (i) P, V to 2P, V (ii) P, V to P, 2V. The work done in the two cases is ______.
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8 m3 of a gas is heated at the pressure 105 N/m2 until its volume increases by 10%. Then, the external work done by the gas is ____________.
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Two cylinders A and B of equal capacity are connected to each other via a stopcock. A contains a gas at standard temperature and pressure. B is completely evacuated. The entire system is thermally insulated. The stopcock is suddenly opened. Answer the following:
What is the final pressure of the gas in A and B?
In insulated systems, the amount of external work done by the gas is proportional to:
n mole of a perfect gas undergoes a cyclic process ABCA (see figure) consisting of the following processes:
A `→` B: Isothermal expansion at temperature T so that the volume is doubled from V1 to V2 = 2V1 and pressure changes from P1 to P2.
B `→` C: Isobaric compression at pressure P2 to initial volume V1.
C `→` A: Isochoric change leading to change of pressure from P2 to P1.
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In thermodynamics, heat and work are ______.
A cyclic process ABCA is shown in the V-T diagram. A process on the P-V diagram is ______.
If a gas is compressed adiabatically:
The molar specific heat of He at constant volume is 12.47 J/mol.K. Two moles of He are heated at constant pressure. So the rise in temperature is 10 K. Find the increase in internal energy of the gas.
What is heat?
A system releases 125 kJ of heat while 104 kJ work is done on the system. Calculate the change in internal energy.
