Tag: pressure in liquids and gases

Quizzes (11) Questions (110)

Questions Related to pressure in liquids and gases

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

Find the ratio of a systolic blood pressure of $120$ (in mm of Hg) to atmospheric pressure. Standard atmospheric pressure is $1.01\times 10^{5}\ Pa$

  1. 0.16

  2. 1.6

  3. 16

  4. 160
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Systolic pressure is 120 mm Hg. Convert this to Pascals: P = h * d * g = 0.12 m * 13600 kg/m^3 * 9.8 m/s^2 = 15993.6 Pa. The ratio to standard atmospheric pressure (1.01 * 10^5 Pa) is 15993.6 / 101000, which is approximately 0.158, rounding to 0.16.

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

On heating water from $0^0 C$ to $100^0 C$ its volume 

  1. Increases at each $^0 C$

  2. First increase till $4^0 C$ and then decreases

  3. First decrease till $4^0 C$ and then increases

  4. Remains same
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Water exhibits anomalous expansion. Its density is maximum at 4 degrees Celsius, meaning its volume is minimum at that temperature. Thus, as it heats from 0 to 4 degrees, it contracts (volume decreases), and from 4 to 100 degrees, it expands (volume increases).

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

The volume of a given amount of water ______ when its temperature is increased form $0^0 C$ to $4^0 C$.

  1. decreases

  2. remains the same

  3. increase

  4. first increases and then decreases.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Due to the anomalous expansion of water, the volume decreases as the temperature rises from 0 degrees Celsius to 4 degrees Celsius, where it reaches its maximum density.

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

A large bottle is fitted with a capillary siphon. Ratio of times taken to empty the bottle when it is filled with (i) water (ii) petroleum of relative density 0.8.

$( _{water} = 0.001poise, _{petroleum} = 0.002 poise, d _{water} = 1000 kg/m^3)$

  1. 5/4

  2. 4/5

  3. 2/5

  4. 3/5
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The time taken to empty a vessel via a siphon is proportional to the viscosity and inversely proportional to the density. The ratio of times t1/t2 = (eta1/eta2) * (d2/d1). Substituting the values: (0.001/0.002) * (800/1000) = 0.5 * 0.8 = 0.4, which is 2/5.

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

Siphon will fail to work if

  1. the densities of the liquid in the two vessels are equal

  2. the level of the liquid in the two vessels are at the same height

  3. both its limbs are of unequal length

  4. the temperature of the liquids in the two vessels are the same
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A siphon works based on the pressure difference created by the difference in liquid levels between two vessels. If the levels are at the same height, there is no pressure difference to drive the flow.

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

A ${ 16cm }^{ 3 }$ volume of water flows per second through a capillary tube of radius r cm and of length 1 cm, when connected to a pressure head of h cm of water. If a tube of the same length and radius r/2 is connected to the same pressure head, find the mass of water flowing per minute through the tube 

  1. 80 gram/min

  2. 70 gram/min

  3. 60 gram/min

  4. 50 gram/min
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

According to Poiseuille's law, flow rate Q is proportional to r^4. If the radius is halved (r/2), the flow rate becomes (1/2)^4 = 1/16 of the original. Original flow = 16 cm^3/s. New flow = 1 cm^3/s. Mass per minute = 1 cm^3/s * 60 s = 60 grams/min.

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

If it takes $5$ minutes to fill a 15 litre bucket  from a water tap of diameter $\frac{2}{\sqrt{\pi}}$ cm then the Reynolds number for the flow is (density of water = $10^3 kg/m^3$ and viscosity of water = $10^{-3}$Pa.s) close to

  1. $11,000$

  2. $550$

  3. $1100$

  4. $5500$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Flow rate = 15L/5min = 3L/min = 0.00005 m³/s. Radius = (2/√π)/100 = 0.0113 m. Velocity = Q/A = 0.00005/(π×0.0113²) ≈ 0.125 m/s. Reynolds = ρvd/η = (10³)(0.125)(0.0226)/(10⁻³) ≈ 2825. Closest to 5500 among options, indicating turbulent flow.

Multiple choice physics floatation pressure in liquids and gases pressure dependence on force and area concept of pressure

Which Newton's laws describe thrust?

  1. First and second

  2. second and third

  3. only second

  4. first and third
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction on that system.