Question

Which of the following is non-conservative force?
A. Electric force
B. Elastic force
C. Viscous force
D. Gravitational force

Answer 1

A conservative force is one in which the total effort required to move a particle between two places is unaffected by the path followed. If a particle moves in a closed loop, the total work done by a conservative force is zero (the sum of the force applied along the route multiplied by the displacement).

Complete answer:
The electrostatic or Coulomb force is conservative, which implies that the work done on q is independent of the path travelled. The gravitational force is precisely identical to this. When a force is conservative, a potential energy associated with the force may be defined.

When an external force is withdrawn from the body of an elastic material, the elastic material returns to its original position and form, implying that no work is done. As a result, the elastic force is clearly a conservative force.Because the gravitational force is conservative, the work done by it on an item is only determined by its change in height.

A conservative force's work is equal to the negative change in potential energy that occurs during the activity. Viscous force is similar to friction in that it resists motion and is non-conservative, but not quite. Total mechanical energy is not preserved since viscous energy is wasted in the form of sound or heat energy.

Hence option C is correct.

Note: Work for a nonconservative force is dependent on the path travelled. An excellent example of a nonconservative force is friction. The amount of work done against friction is determined by the distance between the beginning and terminating positions. There is no potential energy associated with nonconservative forces because of this dependency on route. The work performed by a nonconservative force adds or subtracts mechanical energy from a system, which is an essential property. Friction, for example, generates thermal energy that dissipates, depleting the system's energy.