In a horizontal pipe of a non-uniform cross-section, water flows with a velocity of \(1~\text{ms}^{-1}\)${\mathrm{}}^{}$ at a point where the diameter of the pipe is \(20 ~\text{cm}.\) The velocity of water \((\text{ms}^{-1})\) at a point where the diameter of the pipe is \(5~\text{cm}\) is:
1. \(8\)
2. \(16\)
3. \(24\)
4. \(32\)

A liquid does not wet the solid surface if the angle of contact is :

(1) equal to 45°

(2) equal to 60°

(3) greater than 90°

(4) zero

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

(1) 1.36 m

(2) 13.6 m

(3) 136 m

(4) 0.76 m

Bernoulli's theorem is applicable in the case of:

In a test experiment on a model aeroplane in a wind tunnel, the flow speeds on the upper and lower surfaces of the wing are \(70~\text{ms}^{-1}\) and \(63~\text{ms}^{-1}\) respectively. What is the lift on the wing if its area is \(2.5~\text{m}^2\)? (Take the density of air to be \(1.3 ~\text{kg m}^{-3}\))
1. \(2.5\times 10^5~\text{N}\)
2. \(1.5\times 10^5~\text{N}\)
3. \(2.5\times 10^3~\text{N}\)
4. \(1.5\times 10^3~\text{N}\)

The cylindrical tube of a spray pump has a cross-section of \(8.0\) cm² one end of which has \(40\) fine holes each of diameter \(1.0\) mm. If the liquid flow inside the tube is \(1.5\) m-min^–1,  the speed of ejection of the liquid through the holes is:
1. \(0.64\) ms^-1
2. \(0.74\) ms^-1
3. \(0.54\) ms^-1
4. \(0.84\) ms^-1

A U-shaped wire is dipped in a soap solution and removed. The thin soap film formed between the wire and the light slider supports a weight of \(1.5\times10^{-2}\) N (which includes the small weight of the slider). The length of the slider is \(30\) cm. The surface tension of the film is:

What is the pressure inside the drop of mercury of radius 3.00 mm at room temperature? The surface tension of mercury at that temperature (${20}^0 C$) is 4.65 × 10^–1 N m^–1. The atmospheric pressure is 1.01 × 10⁵ Pa.

$\left(1\right) 2.30\times {10}^5 Pa$
$\left(2\right) 2.01\times {10}^{5 }Pa$
$\left(3\right) 3.01\times {10}^5 Pa$
$\left(4\right) 1.01\times {10}^5 Pa$

The blades of a windmill sweep out a circle of area A. If the wind flows at a velocity v perpendicular to the circle, what is the mass of the air passing through it in time t?

$1. \mathrm{\rho Avt}$
$2. \frac{1}{2}\mathrm{\rho Avt}$
$3. 2 \mathrm{\rho Avt}$
$4. \frac{3}{2} \mathrm{\rho Avt}$

Which one of the following is true from the given statements?