A rise or fall of liquid in a glass tube of a very small diameter when dipped is

ANS:C - directly proportional to the specific weight of liquid

The capillary rise or fall of a liquid in a glass tube is directly proportional to the specific weight of the liquid. Specific weight, also known as unit weight, is defined as the weight per unit volume of a substance. It is directly related to the density of the substance and the acceleration due to gravity. When a glass tube is dipped into a liquid, the rise or fall of the liquid within the tube occurs due to the balance between cohesive forces within the liquid and adhesive forces between the liquid and the solid surface of the tube. This phenomenon is known as capillarity. The capillary rise or fall height ℎh is given by the equation: ℎ = 2γcosθ​ / ρgr where:

• γ is the surface tension of the liquid,
• θ is the contact angle between the liquid and the tube,
• ρ is the density of the liquid,
• g is the acceleration due to gravity, and
• r is the radius of the tube.

The term ρg in the denominator of the equation represents the specific weight of the liquid (ρg=specific weight). This term accounts for the weight of the liquid per unit volume. Therefore, the capillary rise or fall of the liquid in the tube is directly proportional to the specific weight of the liquid. A liquid with a higher specific weight will exhibit a greater capillary rise or fall compared to a liquid with a lower specific weight, all other factors being equal.