When one strikes a safety match, the first step is: from General

Subject

General Knowledge

Class

NDA Class 12

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Sample Papers

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 Multiple Choice QuestionsMultiple Choice Questions

1.

Which one of the following statements is correct?

  • Covalent bonds are directional

  • Ionic bonds are directional

  • Both covalent and ionic bonds are directional

  • Both covalent and ionic bonds are non-directional


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2.

When one strikes a safety match, the first step is:

  • burning of sulphur

  • decomposition of potassium chlorate into potassium chloride and oxygen

  • conversion of a small amount of red phosphorus into white phosphorus

  • burning of glue and starch


C.

conversion of a small amount of red phosphorus into white phosphorus

A match is a small stick of wood or strip of cardboard with a solidified mixture of flammable chemicals deposited on one end. When you strike a match the red phosphorus is converted to white phosphorus for a fraction of a second, just enough to cause a spark of heat by reacting with oxygen in the surrounding air.


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3.

The LPG cooking gas contains propane and butane as the constituents. A sulphur containing compound is added to the LPG, because:

  • it lowers the cost of production

  • it enhances the efficiency of LPG

  • it facilitates easy detection of leakage of the gas

  • it assists in liquefying hydrocarbons


4.

The genetic material of bacteria is found in:

  • nucleus

  • cytoplasm

  • cell membrane

  • ribosome


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5.

A horse and a donkey can breed to produce mule which is an infertile animal. The infertility is because horse and donkey belong to different:

  • class

  • order

  • species

  • genus


6.

A plant having yellow leaves with dead spots has the deficiency of:

  • Potassium

  • Magnesium

  • Nitrate

  • Phosphate


7.

Fluoride toothpaste is sometimes recommended because fluoride:

  • prevents plaque formation

  • hardens the enamel of the tooth

  • kills pathogenic bacteria

  • prevents tooth ache


8.

Along a streamline flow of fluid:

  • the velocity of all fluid particles at a given instant is constant

  • the speed of a fluid particle remains constant

  • the velocity of all fluid particles crossing a given position is constant

  • the velocity of a fluid particle remains constant


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9.

How is the kinetic energy of a moving object affected if the net work done on it is positive?

  • Decreases

  • Increases

  • Remains constant

  • Becomes zero


10.

A particle is executing simple harmonic motion. Which one of the following statements about the acceleration of the oscillating particle is true?

  • It is always in the opposite direction to velocity

  • It is proportional to the frequency of oscillation

  • It is minimum when the speed is maximum

  • It decreases as the potential energy increases


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