Internal Energy of Gas in Adiabatic Compression

Adiabatic processes are those processes in which there is no exchange of heat between the system and the surroundings. In such processes, the change in internal energy is solely due to the work done by or on the system.

Internal energy is the sum of kinetic and potential energies of the particles in the gas. When a gas is compressed adiabatically, the volume of the gas decreases, and the particles are forced to move closer to each other. This leads to an increase in the kinetic energy of the particles, which in turn increases the internal energy of the gas.

Explanation of Options

a) In adiabatic expansion: In adiabatic expansion, the volume of the gas increases, and the particles move away from each other. This leads to a decrease in the kinetic energy of the particles, which in turn decreases the internal energy of the gas.

b) In adiabatic compression: In adiabatic compression, the volume of the gas decreases, and the particles move closer to each other. This leads to an increase in the kinetic energy of the particles, which in turn increases the internal energy of the gas.

c) In isothermal expansion: In isothermal expansion, the temperature of the gas remains constant. The increase in volume is accompanied by a decrease in pressure, and there is no change in the internal energy of the gas.

d) In isothermal compression: In isothermal compression, the temperature of the gas remains constant. The decrease in volume is accompanied by an increase in pressure, and there is no change in the internal energy of the gas.

Conclusion

Thus, the correct answer is option 'B' - the internal energy of the gas increases in adiabatic compression.

B