The two thigh bones (femurs), each of cross-sectional area \(10\) cm² support the upper part of a human body of mass \(40\) kg. The average pressure sustained by the femurs is:
1. \(0.2\times 10^{5}\) Nm^-2
2. \(2\times10^{5}\) Nm^-2
3. \(20\times10^{5}\) Nm^-2
4. \(20\times10^{6}\) 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

The density of the atmosphere at sea level is $1.29 {\mathrm{kgm}}^{-3}$. Assume that it does not change with altitude. Then how high would the atmosphere extend?

1.   8 km

2.   5 km

3.   7 km

4.   6 km

At a depth of 1000 m in an ocean, the force acting on the window of area 20 cm × 20 cm of a submarine is? The interior of the submarine is maintained at sea-level atmospheric pressure. (The density of sea water is 1.03 × 10³ kg m^-3, g = 10 m s^–2)

1.   $4.12\times {10}^4 \mathrm{N}$

2.   $4.12\times {10}^5 \mathrm{N}$

3.   $5.12\times {10}^5 \mathrm{N}$

4.   $5.12\times {10}^4 \mathrm{N}$

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 \(1.0\) cm and \(3.0\) cm respectively. Force exerted on the larger piston when a force of \(10\) N is applied to the smaller piston:
1. \(80\) N
2. \(90\) N
3. \(10\) N
4. \(20\) N

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 cm and 3.0 cm respectively. If the smaller piston is pushed in through 6.0 cm, how much does the larger piston move out?

1.   0.67 cm

2.   6.7 cm

3.   67 cm

4.   6.3 cm

In a car lift, the compressed air exerts a force ${\mathrm{F}}_1$ on a small piston having a radius of 5.0 cm. This pressure is transmitted to the second piston of a radius of 15 cm. If the mass of the car to be lifted is 1350 kg, the pressure necessary to accomplish this task and the force ${\mathrm{F}}_1$, respectively, are?

(g = 9.8 ms^-2)

1.   $1.9\times {10}^6 \mathrm{Pa}$ and 1400 N

2.   $1.9\times {10}^4 \mathrm{Pa}$ and 1580 N

3.   $19\times {10}^5 \mathrm{Pa}$ and 1570 N

4.   $1.9\times {10}^5 \mathrm{Pa}$ and 1470 N