Tag: chemistry

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Multiple choice chemistry air, winds and cyclones the concept of bernoulli's principle air exerts pressure wind and pressure variations in atmospheric pressure wind and rain uneven heating of earth

When a vehicle travels very fast, a region of ______ is created temporarily just behind it.

  1. High pressure

  2. Low pressure

  3. High density

  4. Cyclone
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
When a vehicle moves very fast, a low pressure is produced temporarily and the wind nearby rushes in to fill its place.
Multiple choice chemistry air, winds and cyclones the concept of bernoulli's principle air exerts pressure wind and pressure variations in atmospheric pressure wind and rain uneven heating of earth

Which of the following principle shows that if you increase air speed its pressure will decrease?

  1. Darwin principle

  2. Einstein principle

  3. Bohr principle

  4. Bernoulli's principle
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
According to Bernoulli's principle, Fast moving air equals low air pressure while slow moving air equals high air pressure.
 Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure. The same is applicable in case of gases also.
Multiple choice chemistry air, winds and cyclones the concept of bernoulli's principle air exerts pressure wind and pressure variations in atmospheric pressure wind and rain uneven heating of earth

Increase in air speed is associated with ______________ .

  1. increasein air pressure

  2. decrease in air pressure

  3. increase in air temperature

  4. decrease in air temperature
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The increased wind speed is accompanied by a reduced air pressure.
Multiple choice chemistry air, winds and cyclones the concept of bernoulli's principle air exerts pressure wind and pressure variations in atmospheric pressure wind and rain uneven heating of earth

A piece of paper is kept on the table.  You have to lift it from the table by blowing high-speed air over it. In which direction will you blow the air?

  1. Sideways

  2. In the upward direction

  3. In the downward direction

  4. In the upward direction below the table
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
In order to lift the paper up from the table we need to blow air in sideways.
Multiple choice chemistry air, winds and cyclones the concept of bernoulli's principle air exerts pressure wind and pressure variations in atmospheric pressure wind and rain uneven heating of earth

Two pieces of papers are held parallel. Air is blown with a high speed in between them. Which of the following phenomena will be observed?

  1. The papers will move away from each other.

  2. The papers will move towards each other.

  3. The papers will stay at their position.

  4. The papers will catch fire due to increase in air temperature.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
It seems amazing that the two sheets of paper move closer together, the pressure is reduced where the air is moving quickly. This is called the Bernoulli principle. 
Multiple choice chemistry hydroxy compounds and ethers alcohol nomenclature of alcohols and phenols introduction to alcohols

Tertiary alcohol on treatment with cyanide in presence of conc. ${ H } _{ 2 }{ SO } _{ 4 }$ gives corresponding primary amine. This reaction is called as :

  1. Schmidt reaction

  2. Curtius degradation

  3. Leuckart reaction

  4. Ritter reaction
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The reaction of a tertiary alcohol with hydrogen cyanide in the presence of concentrated sulfuric acid to yield a primary amine is known as the Ritter reaction. It involves the formation of a carbocation intermediate followed by the addition of a nitrile.

Multiple choice chemistry chemical thermodynamics calorific value occurrence of carbon compounds in nature study of enthalpy

What is used to measure the calorific value of a substance?

  1. Barometer

  2. Bomb calorimeter

  3. Spectrometer

  4. Combustion chamber
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Barometer: To measure pressure.

Bomb calorimeter: To measure the heat output of combustion.

Spectrometer: To measure the absorption of light.

Combustion chamber: Chamber used for combustion.