CBSE Questions for Class 11 Engineering Physics Mechanical Properties Of Fluids Quiz 11 - MCQExams.com

A square box of water has a small hole located in one of the bottom corners. When the box is full and sitting on a level surface, complete opening of the hole results in a flow of water with a speed $$v_0$$, as shown in fig. When the box is still half empty, it is tilted by $$45^o$$ so that the hole is at the lowest point. Now the water will flow out with a speed of:
119590.png
  • $$v_0$$
  • $$v_0\cdot 2$$
  • $$\dfrac {v_0}{\sqrt 2}$$
  • $$\dfrac {v_0}{\sqrt [4]{2}}$$
In a cylindrical vessel containing liquid of density $$\rho$$, there are two holes in the side walls at heights of $$h_1$$ and $$h_2$$ respectively such that the range of efflux at the bottom of the vessel is same. Find the height of a hole, for which the range of efflux would be maximum. 
  • $$\dfrac {h_2+h_1}{2}$$
  • $$\dfrac {h_2-h_1}{2}$$
  • $$\dfrac {h_2h_1}{2}$$
  • $$\dfrac {h_2}{h_1}$$
A piston of mass $$M= 3 kg$$ and radius $$R=4 cm$$ has a hole into which a thin pipe of radius $$r= 1 cm$$ is inserted. The piston can enter a cylinder tightly and without friction, and initially it is at the bottom of the cylinder. $$750gm$$ of water is now poured into the pipe so that the piston and pipe are lifted up as show. Then, 

126294_f3918b47439747af89c567b078a847a9.png
  • the height $$H$$ of water in the cylinder is $$\cfrac { 2 }{ \pi }m$$
  • the height $$H$$ of water in the cylinder is $$\cfrac { 11 }{ 32\pi } m$$
  • the height $$h$$ of water in the pipe is $$\cfrac { 2 }{ \pi }m$$
  • the height $$h$$ of water in the pipe is $$\cfrac { 11 }{ 32\pi } m$$
The velocity of efflux is:
119788.png
  • $$10 ms^{-1}$$
  • $$20 ms^{-1}$$
  • $$4 ms^{-1}$$
  • $$35 ms^{-1}$$
A cylindrical vessel of cross-sectional area $$1000 cm^2$$, is fitted with a frictionless piston of mass $$10 kg$$, and filled with water completely. A small hole of cross-sectional area $$10 mm^2$$ is opened at a point $$50 cm$$ deep from the lower surface of the piston. The velocity of efflux from the hole will be
  • $$10.5 m/s$$
  • $$3.4 m/s$$
  • $$0.8 m/s$$
  • $$0.2 m/s$$
A non viscous liquid of constant density $$1000 kg/{ m }^{ 3 }$$ flows in a streamline motion along a tube of variable cross section. The tube is kept inclined in the vertical plane as shown in the figure. The area of cross section of the tube  at two points $$P$$ and $$Q$$ at heights of $$2 m$$ and $$5 m$$ are respectively $$4\times { 10 }^{ -3 }{ m }^{ 2 }$$ and $$8\times { 10 }^{ -3 }{ m }^{ 3 }$$. The velocity of the liquid at point $$P$$ is $$1 m/s$$. Then, 

126455.png
  • work done by pressure per unit volume is $$-29625 J/{ m }^{ 3 }$$
  • work done by pressure per unit volume is $$+29625 J/{ m }^{ 3 }$$
  • work done by gravity is $$-30000 J/{ m }^{ 3 }$$
  • work done by gravity is $$+30000 J/{ m }^{ 3 }$$
Find the height of the water in the long tube above the top when the water stops coming out of the hole.
119810_95a92ccb1ede463688c8852e8e3fbbe2.png
  • $$-2h_0$$
  • $$h_0$$
  • $$h_2$$
  • $$-h_1$$
Find the height $$h_2$$ of the water in the long tube above the top initially.
119805.png
  • $$\dfrac {3p_0}{\rho g}-\dfrac {h_0}{3}$$
  • $$\dfrac {2p_0}{\rho g}-\dfrac {h_0}{2}$$
  • $$\dfrac {p_0}{\rho g}-h_0$$
  • $$\dfrac {p_0}{2\rho g}-2h_0$$
Find the speed with which water comes out of the hole.
119807_f67d22dddf71492bb5d2f5592bcb93a8.png
  • $$\dfrac {1}{\rho}[p_0-\rho g(h_1-2h_0)]^{\dfrac {1}{2}}$$
  • $$\left [\dfrac {2}{\rho}[p_0+\rho g(h_1-h_0)]\right ]^{\dfrac {1}{2}}$$
  • $$\left [\dfrac {3}{\rho}[p_0+\rho g(h_1-h_0)]\right ]^{\dfrac {1}{2}}$$
  • $$\left [\dfrac {4}{\rho}[p_0+\rho g(h_1-h_0)]\right ]^{\dfrac {1}{2}}$$
A tank is filled upto height $$L$$ with a liquid and is placed on a platform of height $$h$$ from the ground. To get maximum range $${ x }_{ m }$$ a small hole is punched at a distance of $$y$$ from the free surface of the liquid. Then

126155.png
  • $${ x }_{ m }=2h$$
  • $${ x }_{ m }=1.5h$$
  • $$y=h$$
  • $$y=0.75h$$
Figure shows a capillary tube of radius $$r$$ dipped into water. If the atmospheric pressure is $$P_0$$, the pressure at point $$A$$ ( just below the meniscus ) is

142641.jpg
  • $$P_0$$
  • $$P_0 + \displaystyle \frac {2S}{r}$$
  • $$P_0 - \displaystyle \frac {2S}{r}$$
  • $$P_0 - \displaystyle \frac {4S}{r}$$
A tank, which is open at the top, contains a liquid up to a height $$H$$. A small hole is made in the side of a tank at a distance y below the liquid surface. The liquid emerging from the hole lands at a distance $$x$$ from the tank.

142555_6f2f3e3e6f0d4aaf84f7ca7e3bf2a29e.png
  • If $$y$$ is increased from zero to $$H$$, $$x$$ will first increase and then decrease.
  • x is maximum for $$y = H/2$$.
  • The maximum value of $$x$$ is $$H$$.
  • The maximum value of $$x$$ will depend on the density of the density of the liquid.
What work should be done in order to squeeze all water from a horizontally located cylinder (figure shown above) during the time $$t$$ by means of a constant force acting on the piston? The volume of water in the cylinder is equal to $$V$$, the cross-sectional area of the orifice to $$s$$, with $$s$$ being considerably less than the piston area. The friction and viscosity are negligibly small.
161243_b1a5fe5e1b204ea685c5113b075a1d67.png
  • $$\displaystyle A=\frac{1}{2}\rho\frac{V^3}{{(St)}^2}$$
  • $$\displaystyle A=\frac{3}{2}\rho\frac{V^3}{{(St)}^2}$$
  • $$\displaystyle A=\frac{5}{2}\rho\frac{3V^3}{{(St)}^2}$$
  • None of these
Air is streaming past a horizontal airplane wing such that its speed is $$90 ms^{-1}$$ at the lower surface and $$120 ms^{-1}$$ over the upper surface. If the wing is 10 m long and has an average width of 2m, the difference of pressure on the two sides and the gross lift on the wing respectively, are (density of air $$=1.3 kg m^{-3})$$
  • 5 Pa, 900 N
  • 95 Pa, 900 N
  • 4095 Pa, 900 N
  • 4095 Pa, 81900 N
A massless conical flask filled with a liquid is kept on a table in a vacuum. The force exerted by the liquid on the base of the flask is $$W_1$$.The force exerted by the flask on the table is $$W_2$$.

142049.jpg
  • $$W_1 = W_2$$
  • $$W_1 > W_2$$
  • $$W_1 < W_2$$
  • The force exerted by the liquid on the walls of the flask is $$\left (W_1 - W_2 \right)$$.
The initial speed of efflux without cylinder is:

220539_3bbab269474141dc9f514af335e7e53c.png
  • $$\displaystyle v=\sqrt{\frac{g}{3}[3H+4h]}$$
  • $$\displaystyle v=\sqrt{\frac{g}{2}[4H+3h]}$$
  • $$\displaystyle v=\sqrt{\frac{g}{2}[3H-4h]}$$
  • None of these
A cylindrical vessel open at the top is 20 cm high and 10 cm in diameter. A circular hole of cross sectional area $$1 cm^{2}$$ is cut at the centre of the bottom of the vessel. Water flows from a tube above it in to the vessel at the rate of $$10^{2} cm^{3}/s$$. The height of water in the vessel under steady state is
(Take $$g= 10m/s^{2}$$)
  • 20cm
  • 15cm
  • 10cm
  • 5cm
The density $$D$$ of the material of the floating cylinder is:

220537_9385d4f80c924425b9941506029cd9b4.png
  • $$5d/4$$
  • $$3d/4$$
  • $$4d/5$$
  • $$4d/3$$
A container of large uniform cross-sectional area $$A$$ resting on a horizontal surface, holds, two immiscible, non-viscous and incompressible liquids of densities $$d$$ and $$2d$$ each of height $$H/2 $$  as shown in the figure. The lower density liquid is open to the atmosphere having pressure $$P_{0}. A$$ homogeneous solid cylinder of length $$ L(L< H /2)$$, cross-sectional area $$A/5 $$ is immersed such that it floats with its axis vertical at the liquid-liquid interface with length $$L/4$$ in the denser liquid.
The cylinder is then removed and the original arrangement is restored. A tiny hole of area $$s(s < < A)$$ is punched on the vertical side of the container at a height $$h(h< H/2)$$. As a result of this, liquid starts flowing out of the hole with a range $$x$$ on the horizontal surface.

The horizontal distance traveled by the liquid, initially, is :

220540_ec1fb027df3c4ee7826add5886e6c338.png
  • $$\sqrt{(3H+4h) h}$$
  • $$\sqrt{(3h+4H) h}$$
  • $$\sqrt{(3H-4h) h}$$
  • $$\sqrt{(3H-3h) h}$$
An open vessel full of water is falling freely under gravity. There is a small hole in one filee of the vessel as shown in the figure. The water which comes out from the hole at the instant when hole is at height H above the ground, strikes the ground at a distance of $$x$$ from $$P$$. Which of the following is correct for the situation described?

220412_c717852756bb4f439b04d1e19c013920.png
  • The value of x is $$\displaystyle 2\sqrt{\frac{2hH}{3}}$$
  • The value of x is $$\displaystyle \sqrt{\frac{4hH}{3}}$$
  • The value of $$x$$ can't be computed from information provided
  • No water comes out from the hole
A spherical ball is dropped in a long column of viscous liquid Which of the following graphs represent the variation of
(i)   gravitational force with time
(ii)  viscous force with time
(iii) net force acting on the bass with time
293450_3d8a37414bdb469eb32454672a3d0dc6.png
  • Q, R, P
  • R, Q, P
  • P, Q, R
  • R, P, Q
A small steel ball falls through a syrup at a constant speed of 10 m/s. If the steel ball is pulled upwards with a force equal to twice its effective weight, how fast will it move upwards?
  • 10 cm/s
  • 20 cm/s
  • 5 cm/s
  • -5 cm/s
Equal volumes of a liquid is poured into containers A and B such that the area of cross-section of container A is double the area of cross-section of container B. If $$P_A$$ and $$P_B$$ are the pressures exerted at the bottom of the containers then $$P_A : P_B = $$__________
  • 1 : 2
  • 1 : 1
  • 3 : 2
  • 2 : 1
A metallic shpere of radius $$\displaystyle 1.0\times 10^{-3}m$$ and density $$\displaystyle 1.0\times 10^{4}kg/m^{3}$$ enters a tank of water after a free fall, falling through a distance of h in the earth's gravitational field. If its velocity remains unchanged after entering water, determine the value of h.
[Given : coefficient of viscosity of water = $$\displaystyle 1.0\times 10^{-3}N-s/m^{2},g=10m/s^{2}$$ and density of water = $$\displaystyle 1.0\times 10^{3}kg/m^{3}$$]
  • 20 m
  • 40 m
  • 80 m
  • 10 m
A cylinder of height h filled with water and is kept on lock of height h/The level of water in the cylinder is kept constant. Four holes numbered 1, 2, 3 and 4 are at the side of the cylinder and at height 0, h/4, h/2 and 3h/4, respectively. When all four holes are opened together, the hole from which water will reach farthest distance on the plane PQ is the hole number.
461156_4542dfd90a854beeb09f1a2cd4818e97.png
  • 1
  • 2
  • 3
  • 4
When pressure is applied through a piston at the top of a closed tube containing water, the pressure is transmitted to:
  • Only the bottom of container
  • All directions
  • Only the side faces and the bottom of the container
  • None of these
A drop of water of radius 0.0015 mm is falling in air. If the coefficient of viscosity of air is $$\displaystyle 1.8\times 10^{-5}kg/m \ s$$, what will be the terminal velocity of the drop? (density of water = $$\displaystyle 1.0\times 10^{3}kg/m^{2}$$ and g = 9.8 N/kg). The density of air can be neglected
  • $$\displaystyle 2.72\times 10^{-4}m/s$$
  • $$\displaystyle 3.72\times 10^{-4}m/s$$
  • $$\displaystyle 0.72\times 10^{-4}m/s$$
  • $$\displaystyle 12.72\times 10^{-4}m/s$$
A given shaped glass tube having uniform cross section is filled with water and is mounted on a rotatable shaft as shown in figure. If the tube is rotated with a constant angular velocity $$\displaystyle \omega $$, then 
430437.png
  • Water levels in both sections A and B go up
  • Water level in section A goes up and that in B comes down
  • Water level in section A comes down and that in B it goes up
  • Water levels remain same in both sections
For a fluid which is flowing steadily in a horizontal tube as shown in the figures, the level in the vertical tubes is best represented by.
A liquid flows along a horizontal pipe AB of uniform cross-section. The difference between the level of the liquid in tubes P and Q is $$10\  cm$$. The diameter of the tubes P and Q are the same. Then:
 ($$\displaystyle \\ g=9.8{ ms }^{ -2 }$$)
475076.PNG
  • level in P is greater than that of Q and velocity of flow is $$1.4 \ m/s$$
  • level in Q is greater than that of P and velocity of flow is $$1.4\  m/s$$
  • level in P is greater than that of Q and velocity of flow is $$0.7\  m/s$$
  • level in Q is greater than that of P and velocity of flow is $$0.7\  m/s$$
In a hydraulic lift, the small piston has an area of $$2 cm^2$$ and the large piston has an area of $$80 cm^2$$. What is the mechanical advantage of the hydraulic lift?

591529.PNG
  • $$40$$
  • $$42$$
  • $$10$$
  • $$4$$
A horizontally oriented tube AB of length $$l$$ rotates with a constant angular velocity $$\omega$$ about a stationary vertical axis OO' passing through the end A (fig). The tube is filled with an ideal fluid. The end A of the tube is open, the closed end B has a very small orifice. Find the velocity of the fluid relative to the tube as a function of the column 'height' $$h$$.  

488190.jpg
  • $$v=\omega\sqrt{h(l-h)}$$
  • $$ v=\omega \sqrt{h(2l-h)} $$
  • $$v=\omega h$$
  • $$ v=\omega \sqrt{2h(l-h)} $$
The area of cross-section of the pump plunger and the press plunger of hydraulic press are $$0.03{m}^{2}$$ and $$9{m}^{2}$$ respectively. How much is the force acting on the pump plunger of the hydraulic press overcomes a load of $$900kgf$$?
  • $$13kgf$$
  • $$3kgf$$
  • $$9kgf$$
  • $$36kgf$$
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 $$A=8 \ mm^2$$ .The narrower part has an area $$a=4 \ mm^2$$.The pressure drop in the artery is 24 Pa. What is the speed of blood in the artery?Density of blood is $$ 1.06\times 10^3 kg/m^3$$.
  • $$13.5\times 10^{-2}\ ms^{-1}$$
  • $$12.5\times 10^{-2}\ ms^{-1}$$
  • $$26.5\times 10^{-3}\ ms^{-1}$$
  • $$32.5\times 10^{-}\ ms^{-1}$$
A liquid flows through two capillary tubes connected in series. Their lengths are $$L$$ and $$2L$$ and radii $$r$$ and $$2r$$ respectively. Then the pressure differences across the first and the second tube are in the ratio
  • $$8:1$$
  • $$4:1$$
  • $$2:1$$
  • $$1:8$$
A capillary tube of radius $$r$$ is immersed in water and water rises to a height of $$h$$. Mass of water in the capillary tube is $$5\times 10^{-3}kg$$. The same capillary tube is now immersed in a liquid whose surface tension is $$\sqrt{2}$$ times the surface tension of water. The angle of contact between the capillary tube and this liquid is $$45^o$$. The mass of liquid which rises into the capillary tube now is (in kg):
  • $$5\times 10^{-3}$$
  • $$2.5\times 10^{-3}$$
  • $$5\sqrt{2}\times 10^{-3}$$
  • $$3.5\times 10^{-3}$$
What is a pressure on the smaller piston if both the pistons are at same horizontal level? (Take $$g=10m$$ $${s}^{-2}$$)
  • $$3Pa$$
  • $$4\times {10}^{3}Pa$$
  • $$6\times {10}^{5}Pa$$
  • $$1000Pa$$
There are two round tables in the physics classroom: one with the radius of $$50\ cm$$, the other with a radius of $$150\ cm$$. What is the relationship between the two forces applied on the tabletops by the atmospheric pressure? then value of $$\dfrac{F_1 }{F_2} $$ is:
  • $$\dfrac{1}{9}$$
  • $$\dfrac{1}{3}$$
  • $$3$$
  • None of the above 
A capillary tube is attached horizontally to a constant pressure head arrangement. If the radius of the capillary tube is increased by $$10$$%, then the rate of flow of the liquid shall change nearly by
  • $$+10$$%
  • $$46$$%
  • $$-10$$%
  • $$-40$$%
Three capillaries of internal radii $$2r$$, $$3r$$ and $$4r$$, all of the same length, are joined end to end. A liquid passes through the combination and the pressure difference across this combination is $$20.2 cm$$ of mercury. The pressure difference across the capillary of internal radius $$2r$$ is
  • $$2 cm$$ of $$Hg$$
  • $$4 cm$$ of $$Hg$$
  • $$8 cm$$ of $$Hg$$
  • $$16 cm$$ of $$Hg$$
 A small hole is made at a height of $$h = \dfrac{1}{2}  m$$ from the bottom of a cylindrical water tank and at a depth of $$h = 2 m$$ from the upper level of water in the tank. The distance, where the water emerging from the hole strikes the ground, is:
599172.png
  • $$22m$$
  • $$1 m$$
  • $$2 m$$
  • None of these.
A tank is filled upto a height $$h$$ with a liquid and is placed on a platform of height $$h$$ from the ground. To get maximum range, $${x}_{m}$$ a small hole is punched at a distance of $$y$$ from the free surface of the liquid. Then
758851_ad56e6adccbc42aabd4e4a5af3fcf8c3.png
  • $${ x }_{ m }=2h$$
  • $${ x }_{ m }=1.5h$$
  • $$v=h$$
  • $$y=0.75h$$
A wooden cylinder of diameter $$4r$$, height $$h$$ and density $$\rho /3$$ is kept on a hole of diameter $$2r$$ of a tank filled with water of density $$\rho$$ as shown in the figure. The height of the base of cylinder from the base of tank is $$H$$. Now level of the liquid starts decreasing slowly. When the level of the liquid is at a height $$h_1$$, above the cylinder the block just starts to lift. At what value of $${h}_{1}$$, will the block rise.
777218_94476d0a8378454b80f42b8510938d09.png
  • $$\cfrac { 4h }{ 9 } $$
  • $$\cfrac { 5h }{ 9 } $$
  • $$\cfrac { 5h }{ 3 } $$
  • None of these
The block is maintained at the position by external means and the level of liquid is lowered. The height $${h}_{2}$$ when the external force reduces to zero is

777222_9b1b24664e85400c90d6071f729866c1.png
  • $$\cfrac { 4h }{ 9 } $$
  • $$\cfrac { 5h }{ 9 } $$
  • $$\cfrac { 2h }{ 3 } $$
  • None of these
Two fully blown balloons are suspended as shown in the diagram. A stream of air is passed in between the balloons. What will happen to the balloons?

930279_f2c9ab027c574b51b6c246233dd8a046.png
  • They will remain as they are
  • They will go apart
  • They will come closer
  • They will go up
In the adjoining figure, the cross-sectional area of the smaller tube is a and the larger tube is 2a. A block of mass 2 m is kept in the smaller tube have the same base area an as that of the tube. The difference between water levels of the two tubes are (density of water is $$\rho$$ and in $${ \rho  }_{ 0 }$$ is atmospheric pressure)
867279_5fbc05e20f7e4c27b9aa563eede0abcb.png
  • $$\dfrac { { \rho }_{ 0 } }{ pg } +\dfrac { m }{ ap }$$
  • $$\dfrac { { \rho }_{ 0 } }{ pg } +\dfrac { m }{ 2ap }$$
  • $$\dfrac { 2m }{ ap } $$
  • $$\dfrac { m }{ ap }$$
The figure shows the commonly observed decrease in diameter of a water stream as it falls from a tap. The tap has internal diameter $${ D }_{ 0 }$$ and is connected to a large tank of water. The surface of the water is at a height b above the end of the tap. By considering the dynamics of a thin "cylinder' of water in the stream answer the following: (ignore any resistance to the flow and any effects of surface tension, given $$\rho _{ w }$$ density of water)
1. Which of the following equation expresses the fact that the flow rate at the tap is the same as at the stream point with diameter D and velocity v (i.e. D in terms of $${ D }_{ 0 }$$, $${ v }_{ 0 }$$ and v will be):
870974_4ccde27150464382a71bc7482263c7cb.png
  • $$D=\dfrac { { D }_{ 0 }{ v }_{ 0 } }{ v }$$
  • $$D=\dfrac { { D }_{ 0 }{ { v }_{ 0 } }^{ 2 } }{ { v }^{ 2 } }$$
  • $$D=\dfrac { { D }_{ 0 }v }{ { v }_{ 0 } }$$
  • $$D={ D }_{ 0 }\sqrt { \dfrac { { v }_{ 0 } }{ v } }$$
A plane is in level flight at constant speed and each of its two wings has an area of 25 m$$^2$$. If the speed of the air on the upper and lower surfaces of the wing are 270 km h$$^{-1}$$ and 234 km h$$^{-1}$$ respectively, then the mass of the plane is (Take the density of the air = 1 kg m$$^{-3}$$)
  • 1550 kg
  • 1750 kg
  • 3500 kg
  • 3200 kg
A narrow tube completely filled with a liquid is lying on a series of cylinders as shown in the figure. Assuming no sliding between any surfaces, the value of acceleration of the cylinders for which liquid will not come out of the tube from anywhere is given by
876581_1011d34d6d89456fbeb20c5afd58efac.png
  • $$\frac{gH}{2L}$$
  • $$\frac{gH}{L}$$
  • $$\frac{2gH}{L}$$
  • $$\frac{gH}{\sqrt{2L}}$$
A liquid flows through a horizontal tube as shown in figure. The velocities of the liquid in the two sections, which have areas of cross-section $$A_1$$ and $$A_2$$, are $$v_1$$ and $$v_2$$, respectively The difference in the levels of the liquid in the two vertical tubes is h. then

937919_cf2ac6198efd4ccfb173d2ff5d0899d6.png
  • $$v_2^2 - v_1^2 = 2gh$$
  • $$v_2^2 + v_1^2 = 2gh$$
  • $$v_2^2 - v_1^2 = gh$$
  • $$v_2^2 + v_1^2 = gh$$
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 11 Engineering Physics Quiz Questions and Answers