Temporary hardness in water is due to which one of the following

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 devices changes low voltage alternating current to high voltage alternating current and vice-versa?

  • Generator

  • Motor

  • Transformer

  • Vibrator


2.

An optical illusion which occurs mainly in deserts during hot summer is based on the principle of

  • Reflection

  • Interference

  • Dispersion

  • Total internal reflection


3.

At which place Earth's magnetic field becomes horizontal?

  • Magnetic meridian

  • Magnetic equator

  • Geographical pole

  • Tropic of Cancer


4.

The speed of a car travelling on a straight road is listed below at successive intervals of 1s:

0 1 2 3 4 Time (s)
0 2 4 6 8 Speed (m/s)

Which of the following is/are correct?

The car travels
1. with a uniform acceleration of 2 m/s2
2. 16m in 4s
3. with an average speed of 4 m/s.

Select the correct answer using the code given below:

  • 1, 2 and 3

  • 2 and 3 only

  • 1 and 2 only

  • 1 only


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5.

The speed of a body that has Mach number more than 1 is

  • supersonic

  • subsonic

  • 300 m/s

  • about 10 m/s


6.

Molecules of which of the following has cage like structure?

1. Diamond
2. Graphite
3. Fullerenes

Select the correct answer using the code given below:

  • 1, 2 and 3

  • 2 and 3 only

  • 2 only

  • 3 only


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7.

Temporary hardness in water is due to which one of the following of Calcium and Magnesium?

  • Hydrogen carbonates

  • Carbonates

  • Chlorides

  • Sulphates


C.

Chlorides

There are two typesof water hardness: temporary and permanent hardness. Temporary hardness is due to the presence of calcium hydrogencarbonate Ca(HCO3)2(aq) and magnesium hydrogencarbonate Mg(HCO3)2(aq).


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8.

Stung by hairs of nettle leaves causes burning pain. This is due to the injection of

  • Acetic acid

  • Methanoic acid

  • Sulphuric acid

  • Hydrochloric acid


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9.

Which one of the following elements is least reactive with water?

  • Lithium

  • Sodium

  • Potassium

  • Cesium


10.

Rutherford's alpha-particle scattering experiment was responsible for the discovery of

  • Electron

  • Proton

  • Nucleus

  • Helium


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