Tag: physics

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

Which of the following factors would help maintain body temperature in cold water?

  1. higher body fat stores.

  2. wearing layers of clothing.

  3. vigorous movement.

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

$Answer:-$ A

If you have higher body fat more fat will be burned and more and more calories of energy are produced inside body to maintain its normal temperature.

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

Which of the following statements is false?

  1. Atmospheric pressure decreases with increasing altitude.

  2. The air is less dense at high altitudes compared to sea level.

  3. The percentage of oxygen in the air decreases with increasing altitude.

  4. Each liter of air contains fewer molecules of gas at increasing altitude.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The percentage of oxygen in the air decreases with increasing altitude.

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

State true or false.
Atmospheric pressure decreases with increase in height.

  1. True

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

It is to be remembered that 

P = Po - Sgh;  here h is the height above the ground level.
Hence atmospheric pressure decreases with increase in height.

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

Which of the following pollutants does not affect lung function in normal adults but causes bronchoconstriction in asthmatics?

  1. ozone

  2. sulfur dioxide

  3. carbon monoxide

  4. None
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sulfur dioxide does not affect lung function in normal adults but causes bronchoconstriction in asthmatics.

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

A narrow uniform glass  tube $80\ cm$ long and open at both ends is half immersed in mercury. Then, the top of the tube is closed and it is taken out of mercury. A column of mercury $22\ cm$ long then remains in the tube. What is the atmospheric pressure?

  1. $60\ cm$ of $Hg$
  2. $70.9\ cm$ of $Hg$
  3. $76\ cm$ of $Hg$
  4. $none$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Using Boyle's Law (P1V1 = P2V2) for the trapped air, the atmospheric pressure can be calculated based on the mercury column height and the tube dimensions.

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

one -meter long tube closed at both the ends is lying horizontally. A mercury column of length 0.1 m is filled in its middle and in rest in two parts air is filled at atmospheric pressure. when the tube is turned to verticle position then displacement of mercury column will be 

  1. 29m

  2. 0.29m

  3. 0.029m

  4. 2.9m
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When the tube is vertical, the pressure difference between the two air columns balances the weight of the mercury column. Using the ideal gas law and the change in volume, the displacement can be calculated.

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

In troposphere, temperature varies linearly with elevation as $T=T _0-ay$, where $T _0$ is the temperature at the earth surface, then:

  1. the pressure does not change with elevation in troposphere

  2. the variation of pressure with elevation is linear
  3. the dimension of $a$ is $[M^0L^{-1}0]$

  4. the pressure is independent of variation with temperature in the given situation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Given T = T0 - ay, the dimension of 'a' must be temperature divided by length (K/L) to make the equation dimensionally consistent.

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

A $2-m3$ weather balloon is loosely filled with helium at $1\ atm (76\ cm\ Hg)$ and at $27^{\circ}C$. At an elevation of $20,000\ ft$, the atmospheric pressure is down to $38\ cm\ Hg$ and the helium has expanded, being under no constraint from the confining bag. If the temperature at this elevation is $-48^{\circ}C$, the gas volume (in $m3)$ is

  1. $3$
  2. $4.28$
  3. $2$
  4. $2.5$
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice physics pressure in fluids and atmospheric pressure common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure

The atmospheric pressure on a hill can be ___ $cm$ of mercury.

  1. $76$
  2. $70$
  3. $79$

  4. can't say
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Pressure at the surface is $76 cm$ of mercury , Also as we up on a hill pressure decrease ,hence pressure will be less than $76 cm$ of mercury.

So the possible answer is $70 cm$ of mercury.