Which of the following statements is incorrect about ultra-sonics ?
These are sounds whose frequencies are higher than 20,000 cycles per second.
These are inaudible to the human ear.
Bats produce ultra-sonic sounds.
Ultra-sonic sounds are produced when ultra-violet light is incident on sea-water.
How electric bulb emits light ?
When the electric current passes through the filament, electrons are emitted. These electrons strike the glass bulb and produce light.
When electric current passes through the filament, a continuous electric discharge takes place between the two filament wires. This electric discharge emits light.
When current passes through the filament, it becomes white hot and, therefore, emits light.
None of these.
What is the quantity of fresh, air required for a man ?
500 cubic feet of air every 10 minutes.
500 cubic feet of air every 20 minutes.
1000 cubic feet of air every 10 minutes.
1000 cubic feet of air every 20 minutes.
Why does not all the ink run out of fountain pen when it is left wwiitthh nib downwards and the cover off ?
Because of a valve in the pen.
Because ink is too viscous to flow out.
Because the atmospheric pressure outside the pen is greater than the pressure inside the pen tube.
Because the atmospheric pressure outside the pen is less than inside the pen tube.
Why do we not see stars in the day light ?
Because of the powerful light of the sun.
Because stars do not emit any )ight in day time.
Because stars are hidden by the sun.
Because stars are hidden by the clouds.
Why rain water is soft but river water is hard ?
Because rain water is free from chemical impufities and river water contains carbonates and chlorides of magnesium and calcium.
Because rain water contains carbonates and chlorides of magnesium and calcium while the river water is freeftom all chemical impurities.
Because rain water contains carbonates of magnesium while the river water contains chlorides of calcium.
Because rain water contains chlorides of magnesium while the river water contains sulphates of calcium.
What is a cloud burst ?
Thundering of a cloud.
A sudden shower of rain over a small area.
Lightning b.-fore rain.
Discharge between cloud and high buildings.
Why is fire extinguished by soda bicarbonate ?
Because soda bicarbonate absorbs all the oxygen of the air surrounding the fire.
Because soda bicarbonate has a cooling effect.
Because soda bicarbonate decomposes to give out carbon dioxide.
Because soda bicarbonate isolates the fire from the sorrounding air.
What is the main constituent of the sun ?
Why does a green object look green ?
Because green object absorbs no colour.
Because green object absorbs all the colours except green. Green colour is reflected. Therefore, the object looks green.
Because green object absorbs only the green light and rejects all other colours.
Because of none of these.
1. World Geography -Test-01
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3. World Geography -Test-03
4. Geography of India -Test-01
5. Geography of India -Test-02
6. Geography of India -Test-03
7. Geography of India -Test-04
8. Geography of India -Test-05
9. History of India - Test - 01
10. History of India - Test - 02
11. History of India - Test - 03
12. History of India - Test - 04
13. History of India - Test - 05
14. History of India - Test - 06
15. History of India - Test - 07
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Palace of Versailles France
This royal chateau was once the centre of French government. Its grand architecture gardens and exhibitions reflect its rich history. Strut like royalty in the hall of mirrors or discover the private chambers of Louis XV hidden within the palace.