Question

On dipping a capillary in water the mass of water that rises in it is 'm'. If another capillary of double the radius of the first is dipped in water, the mass of water raised will be:

• A. m/2
• B. m
• C. 2m
• D. 4m

Answer 1

Answer:

C. 2m

• When a capillary is dipped in water, the water rises due to capillary action.

• The height to which the water rises is inversely proportional to the radius of the capillary.

If the radius of the capillary is doubled, the height to which the water rises will be halved. However, the cross-sectional area of the capillary will increase by a factor of 4.

Since the mass of water raised is directly proportional to the height and the cross-sectional area, the new mass will be:

m' = m × (1/2) × 4 = 2m