Laws of Thermodynamics Physics - Laws of Thermodynamics

An ideal gas goes from the state i to the state fas shown in figure. The work done by the gas during the process:

1. Is positive.
2. Is negative.
3. Is zero.
4. Cannot be obtained from this information.

The first law of thermodynamics is a statement of:

1. Conservation of heat.
2. Conservation of work.
3. Conservation of momentum.
4. Conservation of energy.

Should the internal energy of a system necessarily increase if its temperature is increased?

Calculate the heat absorbed by a system in going through the cyclic process shown in figure.

A force F is applied on a block of mass M. The block is displaced through a distance d in the direction of the force. What is the work done by the force on the block? Does the internal energy change because of this work?

The pressure of a gas changes linearly with volume from 10kPa, 200cc to 50kPa, 50cc.

1. Calculate the work done by the gas.
2. If no heat is supplied or extracted from the gas, what is the change in the internal energy of the gas?

An ideal gas is taken from an initial state i to a final state f in such a way that the ratio of the pressure to the absolute temperature remains constant. What will be the work done by the gas?

The outer surface of a cylinder containing a gas is rubbed vigorously by a polishing machine. The cylinder and its gas become warm. Is the energy transferred to the gas heat or work?

When a system is taken through the process abc shown in figure. 80J of heat is absorbed by the system and 30J of work is done by it. If the system does 10J of work during the process adc, how much heat flows into it during the process?

A substance is taken through the process abc as shown in figure. If the internal energy of the substance increases by 5000J and a heat of 2625cal is given to the system, calculate the value of J.

Should the internal energy of a system necessarily increase if heat is added to it?

What should be the condition for the efficiency of a Carnot engine to be equal to 1?

A cylinder containing a gas is lifted from the first floor to the second floor. What is the amount of work done on the gas? What is the amount of work done by the gas? Is the internal energy of the gas increased? Is the temperature of the gas increased?

When a tyre bursts, the air coming out is cooler than the surrounding air. Explain.

An ideal gas is pumped into a rigid container having diathermic walls so that the temperature remains constant. In a certain time interval, the pressure in the container is doubled. Is the internal energy of the contents of the container also doubled in the interval?

When we rub our hands they become warm. Have we supplied heat to the hands?

A closed bottle contains some liquid. The bottle is shaken vigorously for 5 minutes. It is found that the temperature of the liquid is increased. Is heat transferred to the liquid? Is work done on the liquid? Neglect expansion on heating.

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?

Calculate the increase in the internal energy of 10g of water when it is heated from 0°C to 100°C and converted into steam at 100kPa. The density of steam= 0.6kg/ m^-3. Specific heat capacity of water = 4200J/ kg^-1°C^-1 and the Jatent heat of vaporization of water = 2.25 × 10⁶J/kg^-1.

Consider the cyclic process ABCA, shown in figure. performed on a sample of 2.0 mol of an ideal gas. A total of 1200J of heat is withdrawn from the sample in the process. Find the work done by the gas during the part BC.

Figure. shows a paddle wheel coupled to a mass of 12kg through fixed frictionless pulleys. The paddle is immersed in a liquid of heat capacity 4200JK^-1 kept in an adiabatic container. Consider a time interval in which the 12kg block falls slowly through 70cm.

1. How much heat is given to the liquid?
2. How much work is done on the liquid?
3. Calculate the rise in the temperature of the liquid neglecting the heat capacity of the container and the paddle.

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Figure. shows a cylindrical tube of volume V with adiabatic walls containing an ideal gas. The internal energy of this ideal gas is given by 1.5nRT. The tube is divided into two equal parts by a fixed diathermic wall. Initially, the pressure and the temperature are P₁, T₁ on the left and p₂, T₂ on the right. The system is left for sufficient time so that the temperature becomes equal on the two sides.

1. How much work has been done by the gas on the left part?
2. Find the final pressures on the two sides.
3. Find the final equilibrium temperature.
4. How much heat has flown from the gas on the right to the gas on theleft?