Tag: fluid pressure

Questions Related to fluid pressure

A pump motor is used to deliver water at a certain rate from the given pipe. To obtain 'n' times water from the same pipe in the same time, the amount of power of the motor should be increased to:

physics option b: engineering physics buoyancy floatation fluid pressure

  1. np

  2. ${n^3}$

  3. ${n^2}$

  4. 2np

Show answer
Correct Option: B

Equal amount of same gas in two similar cylinders $A \text { and } B$,compressed to same final volume from same initial volume one adiabatically and another isothermally, respectively then  

physics option b: engineering physics buoyancy floatation fluid pressure

  1. final pressure in $A$ is more than in $B$

  2. final pressure in $B$ is greater than in $A$

  3. final pressure in both able equal

  4. for the gas, value of $\gamma = \frac { C _ { p } } { C _ { V } }$

Show answer
Correct Option: A

Water flows into a large tank with flat bottom at the rate of $  10-4 \mathrm{m}^{3} \mathrm{s}-1  $ . Water is also leaking out
of a hole of area 1 $  \mathrm{cm}^{2}  $ at its bottom. If the height of the water in the tank remains steady, then this height is:

physics option b: engineering physics buoyancy floatation fluid pressure

  1. 4 cm

  2. 2.9 cm

  3. 1.7 cm

  4. 5.1 cm

Show answer
Correct Option: C

The height to which a cylindrical vessel be filled with a homogeneous liquid, to make the average force with which the liquid presses the side of the vessel equal to the force exerted by the liquid on the bottom of the vessel is equal to:

physics option b: engineering physics buoyancy floatation fluid pressure

  1. half of the radius of the vessel.

  2. radius of the vessel.

  3. one-fifth of the radius of the vessel.

  4. three-fourth of the radius of the vessel.

Show answer
Correct Option: B
Explanation:

If $h$ is the height of liquid in cylinder, $r$ be the radius of the cylinder and $\rho$ be the density of the liquid. then we have
weight of the liquid $=\pi { r }^{ 2 }h\rho g          ....... (I)$
Mean pressure on the wall $=\frac{1}{2} \rho g h $
force on the wall $=\frac{1}{2} \rho g h \times 2 \pi r h=\pi r \rho g h^2          ....... (II)$
On equating $(I)$ and $(II)$ we have
$\pi { r }^{ 2 }h\rho g=\pi r \rho g h^2$
$\Rightarrow r=h$
i.e. the liquid should be filled up-to a height equal to the radius of the cylinder.

A thermally insulated cylinder is divided into two equal halves by a thermally insulated wall. One half contains He at 600$\mathrm { K }$ and the other contains $\mathrm { H } _ { 2 }$ at 800$\mathrm { K }$ , pressure being same in two parts equal to $P _ { 0 }$ . Now, the wall is removed and two gases mix. The resulting pressure is

physics option b: engineering physics buoyancy floatation fluid pressure

  1. $P _ { 0 }$

  2. 2$P _ { 0 }$

  3. $\frac { 28 P _ { 0 } } { 54 }$

  4. $\frac { 28 P _ { 0 } } { 27 }$

Show answer
Correct Option: D

Two identical cylinders contain Helium at 2.5atmosphere and Argon at 1 atmosphere respectively. If both gases are transferred in one ofthe cylinders, what is the new pressure? 

physics option b: engineering physics buoyancy floatation fluid pressure

  1. $3.5$ atmosphere

  2. $1.5$ atmosphere

  3. $1.75$ atmosphere

  4. $1$ atmosphere.

Show answer
Correct Option: A

By sucking through a straw, a student can reduce the pressure in his lungs to $750mm$ of $Hg$ (Density $=13.6g/{cm}^{3}$). Using the straw, he can drink water from a glass up to a maximum depth of

physics option b: engineering physics buoyancy floatation fluid pressure

  1. $10cm$

  2. $75cm$

  3. $13.5cm$

  4. $1.36cm$

Show answer
Correct Option: C
Explanation:
Given,
$\rho _H=13.6g/cm^3$
$\rho _w=1g/cm^3$
$P _0=760mm\,  of\,  Hg$
$P _l=750mm\,   of\,  Hg$
The pressure difference between the lungs of student and the atmosphere is given by
$\Delta P=P _0-P _l$
$\Delta P=760-750=10mm \,  of\,   Hg$
$\Delta P=1cm\,  of\,   Hg$
This pressure can be used for the drinking water.
$1cm\,   of\,   Hg=$ Pressure difference due to water column
$\rho _H gh _H=\rho _w gH$
$1\times 13.6\times g=1\times g\times H$
$H=13.6cm $
The correct option is C.

The pressure and temperature of two different gases is $P$ and $T$ having the volume $V$ for each. They are mixed keeping the same volume and temperature, the pressure of the mixture will be

physics option b: engineering physics buoyancy floatation fluid pressure

  1. $P/2$

  2. $P$

  3. $2P$

  4. $4P$

Show answer
Correct Option: C

How much work is done by an agent fcn forcing 3$\mathrm { m } ^ { 3 }$ of water through a pipe of radius 2$\mathrm { cm }$ , It the difference in pressure at the two ends of the pipe is $10 ^ { 4 } \mathrm { N } \mathrm { m } ^ { 2 } \mathrm { ? }$

physics option b: engineering physics buoyancy floatation fluid pressure

  1. $3 \times 10 ^ { 6 } J$

  2. $2 \times 10 ^ { 6 } J$

  3. $4 \times 10 ^ { 5 } J$

  4. $1 \times 10 ^ { 5 } 3$

Show answer
Correct Option: A

A box is divided into two equal compartments by a thin partition and they are filled with gases $  P  $and $  Q  $ respectively. The two compartments have a pressure of 250 torr each. The pressure after removing the partition will be equal to

physics option b: engineering physics buoyancy floatation fluid pressure

  1. $125 torr$

  2. $2.5 torr$

  3. $250 torr$

  4. $500 torr$

Show answer
Correct Option: C