Question

In which process net work done is zero?
This question has multiple correct options
A. Cyclic
B. Isochoric
C. Free expansion
D. Adiabatic

Answer 1

Hint:Work is the energy transferred to or from an object by applying force along with a displacement in physics. It is frequently represented as the product of force and displacement in its simplest form. If a force has a component in the direction of the displacement of the point of application (when applied), it is said to do positive work.

Complete step-by-step solution:
In many ways, the scientific definition of work differs from its everyday meaning. In physics, the definition of work reveals its connection to energy: whenever work is performed, energy is transferred.
The joule $$(J)$$ is the SI unit of work, and it is defined as the work done by a force of $$1$$ Newton in moving an object a distance of $$1$$ meters in the force's direction.
Depending on the direction of displacement of the object concerning the force, the work done by the force can be positive, negative, or zero. The work done by the force of friction on an object moving in the opposite direction to the direction of force, such as friction acting on an object moving forward, is negative.
Option A: Cyclic: The area enclosed in a P-V diagram represents the network involved in a cyclic process. The system is functional if the cycle rotates clockwise. If the clockwise cycle is followed, work on the system is completed every cycle.
Option B: Isochoric: An isochoric process is one in which the volume remains constant (V=constant), implying that the system performs no work. As a result, any heat energy transferred to the system from outside will be absorbed as internal energy in the simple two-dimensional system.
Option C: Free expansion: There is no work done in free expansion because there is no external pressure. A free expansion is an irreversible process in which a gas expands into an insulated evacuated chamber, similar to a container with a piston, and the gas is left to expand in a vacuum.
Option D: Adiabatic: When compared to an isothermal expansion, which has both heat flow and works done, an adiabatic expansion does less work and has no heat flow, resulting in lower internal energy. During adiabatic expansion, the temperature drops.
Thus, in the isocaloric and free expansion process work done is zero.

Note:Work and energy are inextricably linked. According to the work-energy principle, an increase in a rigid body's kinetic energy is caused by an equal amount of positive work done on the body by the resultant force acting on that body. A decrease in kinetic energy is caused by the resultant force doing an equal amount of negative work. As a result, if the network is positive, the particle's kinetic energy increases by the same amount. If the total work done is negative, the particle's kinetic energy is reduced by the same amount.