Why is the upper meniscus of mercury convex in a glass tube?

The coefficient of real expansion of mercury is gamma and the coefficient of linear expansion of glass is alpha . The mercury thread, enclosed in a glass tube of uniform bore, expands linearly due to rise in temperature. The effective coefficient of expansion will be

The diameter of a barometer tube is 3 mm. What will be the error in the barometer reading due to surface tension? For mercury in the glass tube, the surface tension =0.647 N.m^-1 , the angle of contact =128^@ and the density of mercury =13500 kg. m^-3 .

Thermal capacities of mercury and glass of the same volume are equal. Densities of mercury and glass are "13.6 g.cm"^(-3) and "2.5 g.cm"^(-3) respectively. If the specific heat capacity of mercury is "0.03 cal.g"^(-1).^(@)C^(-1) . Find that of glass.

The cross-sectional area of the left limb of a U-tube is one-third of that of its right limb. It contains some mercury. The empty space in the left limb measures to 40 cm. If water is poured to fill it up, then find the rise of the mercury column in the right limb. (Specific gravity of mercury = 13.6)

Why the surface of water in a glass capillary tube is concave whereas it is convex in case mercury?