# Solved papers for NEET Physics Fluid Mechanics, Surface Tension & Viscosity / द्रव यांत्रिकी, भूतल तनाव और चिपचिपापन NEET PYQ-Fluid Mechanics, Surface Tension and Viscosity

### done NEET PYQ-Fluid Mechanics, Surface Tension and Viscosity Total Questions - 13

• question_answer1) The dimensions of universal gravitational constant are:                                [AIPMT (S) 2004]

A)
$[{{M}^{-1}}\,{{L}^{3}}\,{{T}^{-2}}]$

B)
$[M{{L}^{2}}\,{{T}^{-1}}]$

C)
$[{{M}^{-2}}\,{{L}^{3}}\,{{T}^{-2}}]$

D)
$[{{M}^{-2}}\,{{L}^{2}}\,{{T}^{-1}}]$

• question_answer2) The wet ability of a surface by a liquid depends primarily on                         [NEET 2013]

A)
viscosity

B)
surface tension

C)
density

D)
angle of contact between the surface and the liquid

• question_answer3) A certain number of spherical drops of a liquid of radius r coalesce to form a single drop of radius R and volume V. If T is the surface tension of the liquid, then                                                                          [NEET 2014]

A)
Energy $=4VT\left( \frac{1}{r}-\frac{1}{R} \right)$ is released

B)
Energy $=3VT\left( \frac{1}{r}+\frac{1}{R} \right)$ absorbed

C)
Energy $=3VT\left( \frac{1}{r}-\frac{1}{R} \right)$ is released

D)
Energy is neither released nor absorbed

• question_answer4) A wind with speed 40 m/s blows parallel to the roof of a house. The area of the roof is $250\,{{m}^{2}}$. Assuming that the pressure inside the house is atmospheric pressure, the force exerted by the wind on the roof and the direction of the force will be $({{p}_{air}}=1.2kg/{{m}^{3}})$                                                                   [NEET 2015 ]

A)
$4.8\times {{10}^{5}}N,$ downwards

B)
$4.8\times {{10}^{5}}N,$ upwards

C)
$2.4\times {{10}^{5}}N,$ upwards

D)
$2.4\times {{10}^{5}}N,$ downwards

• question_answer5) The cylindrical tube of a spray pump has radius R, one end of which has n fine holes, each of radius r. If the speed of the liquid in the tube is v, the speed of the ejection of the liquid through the holes is          [NEET 2015 (Re)]

A)
$\frac{v{{R}^{2}}}{{{n}^{2}}{{r}^{2}}}$

B)
$\frac{v{{R}^{2}}}{n{{r}^{2}}}$

C)
$\frac{v{{R}^{2}}}{{{n}^{3}}{{r}^{2}}}$

D)
$\frac{{{v}^{2}}R}{nr}$

• question_answer6) The heart of a man pumps 5 L of blood through the arteries per minute at a pressure of 150 mm of mercury. If the density of mercury be $13.6\times {{10}^{3}}kg/{{m}^{3}}$ and $g=10m/{{s}^{2}},$ then the power of heart in watt is                                                                                                                                          [NEET 2015 (Re)]

A)
1.70

B)
2.35

C)
3.0

D)
1.50

• question_answer7) Water rises to a height W in capillary tube. If the length of capillary tube above the surface of water is made less than A, then                                                                                                                                        [NEET 2015 (Re)]

A)
water rises upto the tip of capillary tube and then starts over flowing like a fountain

B)
water rises upto the top of capillary tube and stays there without overflowing

C)
water rises upto a point a little below the top and stays there

D)
water does not rise at all

• question_answer8) Two non-mixing liquids of densities $\rho$ and$n\rho (n>1)$ are put in a container. The height of each liquid is h. A solid cylinder of length L and density d is put in this container. The cylinder floats with its axis vertical and length $pL(p<1)$ in the denser liquid. The density d is equal to                                                                               [NEET - 2016]

A)
$\{1+(n+1)p\}\rho$

B)
$\{2+(n+1)p\}\rho$

C)
$\{2+(n-1)p\}\rho$

D)
$\{1+(n-1)p\}\rho$

• question_answer9)  All tube with both ends open to the atmosphere, is partially filled with water. Oil, which is immiscible with water, is poured into one side until it stands at a distance of 10 mm above the water level on the other side. Meanwhile the water rises by 65 mm from its original level (see diagram). The density of the oil is                                             [NEET-2017]

A)
$928\,\,kg\,\,{{m}^{-3}}$

B)
$650\,\,kg\,\,{{m}^{-3}}$

C)
$425\,\,kg\,\,{{m}^{-3}}$

D)
$800\,\,kg\,\,{{m}^{-3}}$

• question_answer10) A small sphere of radius 'r' falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity, is proportional to                               [NEET - 2018]

A)
${{\text{r}}^{\text{5}}}$

B)
${{\text{r}}^{\text{2}}}$

C)
${{\text{r}}^{\text{3}}}$

D)
${{\text{r}}^{\text{4}}}$

• question_answer11) A small hole of area of cross-section 2 $m{{m}^{2}}$is present near the bottom of a fully filled open tank of height 2 m. Taking$g=10\text{ }m/{{s}^{2}}$, the rate of flow of water through the open hole would be nearly:  [NEET 2019]

A)
$2.23\times {{10}^{6}}\text{ }{{m}^{3}}/s$

B)
$6.4\times {{10}^{6}}\text{ }{{m}^{3}}/s$

C)
$12.6\times {{10}^{6}}\text{ }{{m}^{3}}/s$

D)
$8.9\times {{10}^{6}}\text{ }{{m}^{3}}/s$

• question_answer12) A soap bubble, having radius of 1 mm, is blown from a detergent solution having a surface tension of $2.5\times {{10}^{2}}$N/m. The pressure inside the bubble equals at a point ${{Z}_{0}}$below the free surface of water in a container. Taking$g=10\text{ }m/{{s}^{2}}$, density of water$={{10}^{3}}kg/{{m}^{3}}$, the value of ${{Z}_{0}}$ is:                                                                                                                          [NEET 2019]

A)
1 cm

B)
0.5 cm

C)
100 cm

D)
10 cm

• question_answer13) A capillary tube of radius r is immersed in water and water rises in it to a height h. The mass of the water in the capillary is 5 g. Another capillary tube of radius 2r is immersed in water. The mass of water that will rise in this tube is: [NEET 2020]

A)
5.0 g

B)
10.0 g

C)
20.0 g

D)
2.5 g