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

Atmospheric pressure is measured by

  1. Barometer

  2. Manometer

  3. Screw gauge

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is A.

A barometer is a scientific instrument used in meteorology to measure atmospheric pressure. A simple barometer consists of a long glass tube (closed at one end, open at the other) filled with mercury and turned upside down into a container of mercury. The barometer works by balancing the mercury in the glass tube against the outside air pressure, just like a set of scales. As air pressure increasesthat is, as the air becomes heavierit pushes more of the mercury up into the tube. As air pressure decreases, more of the mercury drains from the tube. So the level of mercury in the tube provides a precise measure of air pressure.

Multiple choice physics pressure in liquids and gases common consequences of the atmospheric pressure atmospheric pressure and its consequences important points about atmospheric pressure
Air creates as much pressure as created by ....... $cm$ of vertical height of mercury column in a simple barometer.
  1. $22$
  2. $36$
  3. $76$
  4. $260$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The height to which mercury rises in simple barometer is $76cm$.

This is the reason that  atmospheric pressure is often expressed as $76cm$ of Hg at sea level.

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

Hydraulic brakes are based on.

  1. Dulong and Petit's law

  2. Pascal's law

  3. Pressure law

  4. Dalton's law of partial pressure
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hydraulic brakes operate on the principle of Pascal's law, which states that pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and the walls of the container. This allows a small force applied at the pedal to be multiplied into a large force at the brake pads.

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

They does the mercury column in the barometer fall rapidly before a severe storm?

  1. It is due to the fall in atmospheric pressure

  2. It is due to the rise in atmospheric pressure

  3. It is due to decrease in humidity in air

  4. It is due to the severe heat energy from the sun
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The mercury column in the barometer fall rapidly before a severe storm, It is due to Fall in the atmospheric pressure. In general, a falling barometer indicates the approach of a storm. If the mercury is over 30.20 inches but falling quickly, warmer, cloudier weather is coming 

Hence option A is a right answer

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 vertical height of the mercury column in a barometer remains unaffected even if the tube is tilted.

  1. True

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

Tilting of tube does not brings any change in height  as  pressure depends on height and as it is not changing. 

so given statement is true
so option (A) is correct .

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 height of a barometer at a temperature of $30^{o}$ appears to be $76\ cm$ according to the brass scale which gives correct reading at $0^{o}C$. $(\alpha _{Brass}=19\times 10^{-6}/ , \gamma _{Hg}=180\times 10^{-6}/ )$ 

  1. $74.22\ cm$
  2. $77.44\ cm$
  3. $78.49\ cm$
  4. $79.94\ cm$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The apparent height of the mercury column is affected by the thermal expansion of both the mercury and the brass scale. Using the formula for corrected height H = H_obs * (1 + gamma*deltaT) / (1 + alpha*deltaT), where gamma is the expansion of mercury and alpha is the expansion of brass, the calculation yields approximately 74.22 cm.

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

When a barometer reading suddenly recedes it indicates that climate:

  1. will be very warm

  2. will be extremely stormy

  3. will remain cold
  4. incessant rain for at least $48$ hours.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In summer, when the barometer falls suddenly, a thunderstorm can be expected, and if it does not rise again upon its cessation, the weather will probably continue unsettled for several days. In summer, when a thunderstorm happens, there is little or no depression of the barometer.