Tag: pressure in liquids and gases

Questions Related to pressure in liquids and gases

Fill in the blank.

The force acting on a unit area of a surface is called____.

physics statics and dynamics of fluid (liquid and gas) pressure in liquids and gases pressure dependence on force and area concept of pressure

  1. atmospheric pressure

  2. pressure

  3. muscular force

  4. none of these

Show answer
Correct Option: B
Explanation:

Pressure is force acting on a unit area of a surface when force applied on object in a particular area of object exert pressure on it.

A force is called thrust when it acts

physics statics and dynamics of fluid (liquid and gas) pressure in liquids and gases pressure dependence on force and area concept of pressure

  1. normal to the surface

  2. inclined to the surface

  3. parallel to the surface

  4. at any arbitrary direction on the surface

Show answer
Correct Option: A
Explanation:

When a force acts vertically downwards or normal to the surface under consideration, it is called thrust.

The commonly used barometric liquid in a barometer is Mercury.

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

Show answer
Correct Option: A
Explanation:

commonly used barometer to measure pressure is filled with mercury such that 1 atm = 76 cm of Hg .

so option (A) is correct .

________ is an instrument used to measure the 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. Barometer

  2. Calorimeter

  3. Thermometer

  4. Speedometer

Show answer
Correct Option: A
Explanation:

Barometer is the instrument used to measure atmospheric pressure.

calorimeter and thermometer is used to measure temperatture.
speedometer is used to measure the speed of the vehicles.
so option (A) is correct

A barometric liquid having high density produces a shorter column of liquid.

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

Show answer
Correct Option: A
Explanation:

 pressure = $\rho$gh 

pressure remains constant so as $\rho$ will increase height will be shortened to get the same pressure .
so given statement is true , hence option (A) is correct

The space above the mercury column in a barometer is torricellian vacuum.

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

Show answer
Correct Option: A
Explanation:

torricellian vacuum is the vaccum formed above the column of mercury in a barometer.

so opton (A) is correct

A barometer reads mercury level of $72\ cm$ at a location above sea level. If someone turns barometer  tube by $37^{o}$ with vertical, find the new reading of barometer.

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

  1. $76\ cm$

  2. $72\ cm$

  3. $90\ cm$

  4. $68\ cm$

Show answer
Correct Option: C

The empty space above mercury in a simple barometer is called _______vaccum

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

  1. pressure

  2. barometric

  3. torricellian

  4. mercuric

Show answer
Correct Option: C
Explanation:

Torricellian vacuum
The vacuum formed when a long tube, closed at one end and filled with mercury, is inverted into a mercury reservoir so that the open end of the tube is below the surface of the mercury. The pressure inside the Torricellian vacuum is the vapour pressure of mercury, about $103\ torr.$

The space above the mercury in a simple barometer is called 

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

  1. Torcelian vacuum

  2. Newton's vacuum

  3. Archimede's vacuum

  4. None of these

Show answer
Correct Option: A
Explanation:

Torricellian vacuum
The vacuum formed when a long tube, closed at one end and filled with mercury, is inverted into a mercury reservoir so that the open end of the tube is below the surface of the mercury. The pressure inside the Torricellian vacuum is the vapour pressure of mercury, about 103 torr.

The moisture present in mercury ______ the barometric height of simple barometer

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. doesn't change

  4. can't say

Show answer
Correct Option: A
Explanation:

The instrument that measures air pressure is a barometer.  There are two types of barometers, mercury and aneroid. In 1643, Toricelli invented the mercury barometer when he inserted a glass tube in a dish of mercury and observed the day-to-day variations in the height of the mercury column. When the atmospheric pressure was high, the greatest pressure was exerted on the mercury in the dish, causing the mercury in the glass tube to rise.  When the pressure was low, the mercury in the glass tube fell. The contemporary aneroid barometer employs a vacuum chamber sensitive to external pressure changes.  Contraction and expansion of the vacuum chamber, linked mechanically to an indicator needle, move the needle clockwise when the pressure rises and counter clockwise when the pressure falls.