Q1: __________ forces do not act in case of fluids.

ANS:D - Tensile

The correct answer is "Tensile" forces do not act in case of fluids. Explanation:

• Vibratory forces: These forces arise due to vibrations or oscillations of particles within a fluid medium. For example, in a vibrating system, particles may experience vibratory forces.
• Centrifugal forces: These forces are experienced by particles in a rotating reference frame. In a rotating system, particles tend to move away from the center of rotation due to centrifugal forces.
• Elastic forces: These forces arise due to the deformation of solid materials. When solids are subjected to external forces, they deform elastically, and elastic forces develop within the material.
• Tensile forces: These forces act to stretch or pull apart a material. In the context of fluids, tensile forces are not applicable because fluids are not typically subject to tensile stress. Instead, fluids can experience compressive stress, shear stress, and pressure but not tensile stress. Tensile forces are more relevant in the context of solid materials.