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Q:

The process that takes place in the atom bomb is

A) nuclear fusion B) nuclear fission
C) radioactive disintegration D) chemical decomposition
 
Answer & Explanation Answer: B) nuclear fission

Explanation:

In the atom bomb, isotopes of uranium are  disintegrated with the release of a large amount of energy. Hence, the process is nuclear fission.

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Filed Under: Chemistry

Q:

Alum is used 

A) as an analgesic B) in the purification of water
C) as a fertilizer D) as a disinfectant
 
Answer & Explanation Answer: B) in the purification of water

Explanation:

Alum is a common alum, potassium aluminum sulphate K2SO4.Al2SO43.24H2O which makes colloidally suspended impurities in water such as clay to settle down.

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Filed Under: Chemistry
Exam Prep: AIEEE

Q:

An element which is preserved under water is 

A) sodium B) sulphur
C) red phosphorus D) white phosphorus
 
Answer & Explanation Answer: D) white phosphorus

Explanation:

White phosphorus undergoes spontaneous combustion when exposed to air. In order to prevent this spontaneous ignition, it is preserved under water. 

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Q:

Which of the following is called 'the King of Chemicals' ?

A) Nitric acid B) Hydrochloric acid
C) Silver nitrate D) Sulphuric acid
 
Answer & Explanation Answer: D) Sulphuric acid

Explanation:

Sulphuric acid is called the King of Chemicals because it is used in the preparation of a very large number of other useful chemicals such as hydrochloric acid, nitric acid, dyes, drugs etc. In fact the annual production of shulpuric acid in a country is a measure of the economy of the country.

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Q:

According to the modern Periodic Law, the properties of elements are periodic functions of their

A) volency B) atomic mass
C) number of neutrons D) atomic number
 
Answer & Explanation Answer: D) atomic number

Explanation:

Atomic number is the serial number of an element in the periodic classification of elements. It gives the number of protons and also the number of electrons in an atom.

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Filed Under: Chemistry

Q:

Washing soda is 

A) sodium hydroxide B) sodium carbonate
C) sodium bicorbonate D) Potassium chloride
 
Answer & Explanation Answer: B) sodium carbonate

Explanation:

Sodium hydroxide - NaOH is caustic soda

 

Sodium carbonate - Na2CO3 is washing soda

 

Sodium bicarbonate - NaHCO3  is baking soda 

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Filed Under: Chemistry
Exam Prep: AIEEE

Q:

A nuclear reactor is said to have become 'critical' when 

A) it stops due to malfunctioning B) it starts emitting dangerous radioactive radiations
C) it is shut down to avoid explosion D) it is ready to produce controlled energy
 
Answer & Explanation Answer: D) it is ready to produce controlled energy

Explanation:

To produce controlled energy i.e energy at a controlled or steady rate, the number of fissions per second must be controlled and maintained at that rate. Excess neutrons should be absorbed by control roads like cadmium.

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Filed Under: Physics

Q:

The electrical domestic tube light gives white fluorescent light because of

A) colision between molecules of filled gas under electric current B) heavy current
C) vacuum inside the tube D) falling of ultra violet rays on the white inner coating of the tube
 
Answer & Explanation Answer: D) falling of ultra violet rays on the white inner coating of the tube

Explanation:

The ultraviolet rays have high frequency and shorter wavelength are converted to visible white light with lower frequency and greater wave length

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Filed Under: Physics