Tag: pressure

Quizzes (17) Questions (42)

Questions Related to pressure

Multiple choice physics pressure pressure in air introduction to atmospheric pressure pressure exerted by air devices to measure pressure

A cubical vessel sealed vessel with edge $L$ is placed on a cart, which is moving horizontally with an acceleration `a' as shown iin figure. The cube is filled with an ideal fluid having density $\rho$. Find the gauge pressure at the centre of the cubical vessel.

  1. $\dfrac{Ldg}2$
  2. $\dfrac{Ld(g+a)}2$
  3. $\dfrac{Lda}2$
  4. $\dfrac{Ld(g-a)}2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In an accelerating frame, the effective gravity is the vector sum of g and -a. At the center of a cube of side L, the depth from the free surface is L/2. Thus, pressure P = rho * g_eff * depth = rho * sqrt(g^2 + a^2) * L/2. However, assuming horizontal acceleration, the pressure gradient leads to P = rho * (g+a) * L/2 if considering vertical and horizontal components combined or specific orientation.

Multiple choice physics pressure pressure in air introduction to atmospheric pressure pressure exerted by air devices to measure pressure

State whether given statement is True or False
You find your mass to be $42$kg on a weighing machine. Is your mass more or less than $42$kg?

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When you weigh your body, an upward buoyant force acts on your body due to the air (a fluid) present around you. As a result, the body gets pushed slightly upwards, causing the weighing machine to show a reading slightly less than the actual value.

Multiple choice physics pressure pressure in air introduction to atmospheric pressure pressure exerted by air devices to measure pressure

State whether true or false:

A sheet of paper falls slower than one that is crumpled into a ball.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sheet crumpled into a ball has a small surface area as compared to the similar unfolded sheet. Therefore, unfolded sheet will experience more resistance due to air as compared to the sheet crumpled into a ball, inspite of same force of gravity acting upon them. It is larger resistance of air which slows down the unfolded sheet, and therefore it falls slower as compared to sheet crumpled into a ball.

Multiple choice physics pressure pressure in fluids pressure in liquids introduction to pressure

The Pressure at any point in the liquid is proportional to :

  1. The density of liquid.

  2. The depth of point below the surface.

  3. The acceleration due to gravity.

  4. All the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pressure at any point in the liquid $(P)=hdg$
i.e., $P\alpha h$
(depth of point below the surface)
$\alpha d$ (density of liquid)
$\alpha g$ (acceleration due to gravity)

Multiple choice physics pressure pressure in fluids pressure in liquids introduction to pressure

Liquid pressure at a point in a liquid does not depend on the :

  1. Density of liquid

  2. Shape of the vessel in which the liquid is kept

  3. Depth of the point from the surface

  4. Acceleration due to gravity
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

pressure in a fluid = $\rho gh $ 

so clearly it is independent of the shape of the vessel in which the liquid is kept .
hence option (B) is correct .

Multiple choice physics pressure pressure in fluids pressure in liquids introduction to pressure

Extremely small pollen grains in water are viewed through a microscope. The grains are seen to
move continually and randomly.
What is the reason for this random movement?

  1. The grains are moved by randomly moving water molecules

  2. The grains are moved by random convection currents in the water

  3. The grains are moved by random rays of light reflecting off them

  4. The grains are moved by the random motion of their own atoms
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is due to brownian motion of fluid particles. The pollen get hitted by the water molecules and carried away by them. 

This is reason behind the random motion of pollen grains in water .

Multiple choice physics pressure pressure in fluids pressure in liquids introduction to pressure

A hose shoots water straight up to a height of $2.5m$. The opening end of the hose an area of $0.75\ cm^{2}$. How much water will come out in one minute ?

  1. $21.5\ litre$
  2. $25\ litre$
  3. $30\ litre$
  4. $31.5\ litre$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Using Bernoulli's equation, the velocity of water exiting the nozzle is v = sqrt(2gh) = sqrt(2 * 9.8 * 2.5) or using g = 9.8/10 approx. The volumetric flow rate is Q = A * v. Integrating over one minute gives the total volume, which computes to 31.5 liters.

Multiple choice physics pressure pressure in fluids pressure in liquids introduction to pressure

Fill in the blank spaces by choosing the correct words from the options given below.

The hulls of the______are made very strong to withstand huge pressure exerted by the sea water. 

  1. $liquids$
  2. $gases$
  3. $submarines$

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Submarines.
The hull of Submarines are specially Strengthened to prevent it from collapsing from the high pressure of the water outside while submerged. Roughly every $30$ feet of depth under water adds another atmosphere of inward pressure on the hull.