Tag: pressure in liquids and gases

Questions Related to pressure in liquids and gases

The atmospheric pressure and height of barometer column is $10^5 P _a$ and 760mm respectively on the earth surface. If the barometer is taken to moon then column height will be

physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. zero

  2. 76 mm

  3. 126.6 mm

  4. 760 mm

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Correct Option: A
Explanation:

Since there is no atmosphere on moon, no atmospheric pressure will be there and hence corresponding to 0 pressure, height of mercury column will be 0.


Answer is option A.

Fill in blanks. 
Atmosphere pressure _________ with increase in altitude 

physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. increases

  2. decreases

  3. remains same

  4. cannot be determined

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Correct Option: B
Explanation:

Pressure with Height: pressure decreases with increasing altitude. The pressure at any level in the atmosphere may be interpreted as the total weight of the air above a unit area at any elevation. At higher elevations, there are fewer air molecules above a given surface than a similar surface at lower levels. For example, there are fewer molecules above the 50 km surface that are found above the 12 km surface, which is why the pressure is less at 50 km.

Hence, Atmosphere pressure decrease with an increase in altitude 

By blowing between two balloons hanging close to each other you observe that they come closer. A similar phenomenon is seen in

physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. The lifting of an aeroplane

  2. Kite flying

  3. The lifting of balloon filled with

  4. Take off of rocket

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Correct Option: A
Explanation:

Due to present difference.

As we go higher and higher atmospheric pressure _______.

physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. Increases

  2. Decreases

  3. Remains Same

  4. None of these

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Correct Option: B
Explanation:

As we go to higher attitudes, atmospheric pressure decreases due to less air molecules on comparision to that at sea level. 

Atmospheric pressure decreases with increase in height.

physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. True

  2. False

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Correct Option: A
Explanation:

Atmospheric pressure decreases with increase in height & pressure at a point at height h.

               P = Po - Sgh.

A given mass of gas occupies a volume $100 c.c$ at one atmosphere pressure and temperature of $100^oC$. Temperature being the same, the volume of the gas atmosphere pressure is

physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. $100 c.c$

  2. $400c.c$

  3. $25c.c$

  4. $200c.c$

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Correct Option: B

The density of the atmosphere at sea level is 1.29 $kg/m^{2}$. assume that it does not change with altitude. then how high would the atmosphere extend?

physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. 3 km

  2. 7 km

  3. 8 km

  4. 9 km

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Correct Option: C
Explanation:
We know that $p=pgh$
p is atmospheric pressure, g in acceration due to gravity
$p = 1.29 kg/m^{2} ; p-=1.013\times 10\, N/m$
$\therefore h=\dfrac{p}{pg}=\dfrac{1.013\times 10^{5}}{1.29\times 9.8}$  $= 8013 \,km$
hence atmospheric extended 8013 km high from the sea level

we do not get crushed by the atmospheric pressure as the out internal pressure and the atmospheric pressure are?

physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. equal

  2. greater

  3. lower

  4. none of the above

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Correct Option: A

Atmospheric pressure decreases with altitude.

physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. True

  2. False

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Correct Option: A

The pressure P of a gas and its mean translational KE per unit volume are related as:

physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

  1. $P=\dfrac{1}{2}E$

  2. $P=E$

  3. $P=\dfrac{3}{2}E$

  4. $P=(\dfrac{2}{3})E$

Show answer
Correct Option: C
Explanation:

$\begin{array}{l} \therefore \, \, { V _{ rms } }=\sqrt { \dfrac { { 3PV } }{ M }  }  \ E=\dfrac { 1 }{ 2 } M\, \, { V _{ rms } }^{ 2 }=\dfrac { 3 }{ 2 } PV=\dfrac { 3 }{ 2 } P\, \, \left[ { \therefore \, \, V=1 } \right]  \end{array}$

Ans. (C)