An optical illusion which occurs mainly in deserts during hot sum

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


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2.

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

  • Reflection

  • Interference

  • Dispersion

  • Total internal reflection


D.

Total internal reflection

When any light ray enters from optically denser medium to optically rarer medium then due to refraction, light ray bends away from the normal. But as well as the values of angles of incidence are increased, the light bending away from the normal becomes more and more away. Thus value of angle of refraction is in increasing order.


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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


7.

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

  • Hydrogen carbonates

  • Carbonates

  • Chlorides

  • Sulphates


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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