The effect of a particle in a fluid attaining its terminal velocity is that the

Answer Details

When a particle falls through a fluid, it experiences a resistance force due to the friction between the particle and the fluid. This resistance force increases as the velocity of the particle increases, until it reaches a point where the resistance force is equal to the force of gravity on the particle.
At this point, the particle stops accelerating and falls at a constant velocity called the terminal velocity. Therefore, when a particle attains its terminal velocity in a fluid, the acceleration becomes zero, and the weight of the particle is balanced by the retarding force due to the viscosity of the fluid.
This means that "weight is equal to the retarding force," is the correct answer. "acceleration is maximum," is incorrect because the particle has stopped accelerating. "buoyancy force is equal to the viscous retarding force," is not necessarily true, as the buoyancy force may be negligible in some situations. "buoyancy force is more than the weight of the fluid displaced," is also not necessarily true, as the buoyancy force may be less than the weight of the fluid displaced in some situations.