A liquid does not wet the solid surface if the angle of contact is:
1. equal to $\mathrm{}$\(45^{\circ}\)
2. equal to \(60^{\circ}\)$\mathrm{}$
3. greater then \(90^{\circ}\)$\mathrm{}$
4. zero 

A barometer is constructed using a liquid (density = \(760~\text{kg/m}^3\)). What would be the height of the liquid column, when a mercury barometer reads \(76~\text{cm}?\) 
(the density of mercury = \(13600~\text{kg/m}^3\))

The two thigh bones (femurs), each of cross-sectional area \(10~\text{cm}^2\) support the upper part of a human body of mass \(40~\text{kg}.\) The average pressure sustained by the femurs is:
1. \(0.2\times 10^{5}~\text{Nm}^{-2}\) 
2. \(2\times10^{5}~\text{Nm}^{-2}\) 
3. \(20\times10^{5}~\text{Nm}^{-2}\) 
4. \(20\times10^{6}~\text{Nm}^{-2}\) 

Pressure on a swimmer \(10\) m below the surface of a lake is:
(Atmospheric pressure= \(1.01\times10^{5}\) Pa, density of water = \(1000\) kg/m³ and \(g=10\) m/s²)
1. \(5\) atm
2. \(4\) atm
3. \(2\) atm
4. \(3\) atm

Two syringes of different cross-sections (without needles) filled with water are connected with a tightly fitted rubber tube filled with water. Diameters of the smaller piston and larger piston are \(1.0~\text {cm}\) and \(3.0~\text{cm}\) respectively. Force exerted on the larger piston when a force of \(10~\text N\) is applied to the smaller piston:
1. \(80~\text N\)
2. \(90~\text N\)
3. \(10~\text N\)
4. \(20~\text N\)

The flow of blood in a large artery of an anesthetised dog is diverted through a Venturi meter. The wider part of the meter has a cross-sectional area equal to that of the artery. A = 8 ${\mathrm{mm}}^2$. The narrower part has an area a = 4 ${\mathrm{mm}}^2$. The pressure drop in the artery is 24 Pa. What is the speed of the blood in the artery?

(Density of blood = $1.06\times {10}^3 \mathrm{kg} {\mathrm{m}}^{-3}$)

1.   145 m/s

2.   0.145 m/s

3.   123 m/s

4.   0.123 m/s