History Exam

Consider the following statements: Hard water is not suitable for 1. Drinking 2. Washing clothes with soap 3. Use in boilers 4. Irrigating crops Which of these statements are correct?

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1 and 3
2 and 3
1, 2 and 4
1, 2, 3 and 4

Which one of the following is not correct?

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Theory of evolution was propounded by Charles Darwin
The breaking apart of the nucleus of an atom is called fusion
Dry ice is nothing but solid carbon dioxide
Telephone was invented by Graham Bell

Helium is preferred to hydrogen in air balloons because it

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Is cheaper
Is less dense
Has greater lifting power
Does not form an explosive mixture with air

Which of the following substances is/are ozone depleting? Select the correct answer from the codes given below: 1. Chlorofluorocarbons 2. Halons 3. Carbon tetrachloride

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1 only
1 and 2 only
2 and 3 only
1, 2 and 3

Which one of the following sets of elements was primarily responsible for the origin of life on the Earth?

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Hydrogen, oxygen, sodium
Carbon, hydrogen, nitrogen
Oxygen, calcium, phosphorus
Carbon, hydrogen, potassium

The order of appearance of the following with increasing temperature during the refining of crude oil is

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Kerosene, gasoline, diesel
Diesel, gasoline, kerosene
Gasoline, kerosene, diesel
Gasoline, diesel, kerosene

In the process of electroplating a utensil with zinc,

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The utensil is made the cathode
Pure zinc is made the anode
The utensil is made the cathode and pure zinc is made the anode
The utensil is made the anode and pure zinc is made the cathode

Consider the following statements and select the correct code. Assertion (A): A chemical reaction becomes faster at higher temperature. Reason (R): At higher temperature, molecular motion becomes more rapid.

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Both A and R are true and R is the correct explanation of A
Both A and R are true, but R is not correct explanation of A
A is true, but R is false
A is false, but R is true

Consider the following statements: Assertion (A): LPG is a pollution free vehicular fuel. Reason (R): Plying of CNG fuelled-buses is recommended for metropolitan cities in India.

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Both A and R are true, and R is the correct explanation of A
Both A and R are true, but R is not the correct explanation of A
A is true, but R is false
A is false, but R is true

What is the role of ultraviolet (UV) radiation in the water purification system? 1. It inactivates / kills the harmful micro- organisms in water. 2. It removes all the undesirable odours from the water. 3. It quickens the sedimentation of solid particles and improves the clarity of water. Which of the statements given above is/are correct?

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1 only
2 and 3 only
1 and 3 only
1, 2 and 3

Domestic cooking gas consists of mostly

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Methane and ethane
Liquified butane and isobutane
Ethylene and carbon monoxide
Hydrogen and acetylene

Enriched uranium is

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Uranium rods kept under special shield
Natural uranium in which the component of radioactive isotope U235 is artificial increased
Natural uranium mixed with thorium
Uranium rods coated with chromium

Hydrogen bomb is based on the principle of

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Controlled fusion reaction
Uncontrolled fusion reaction
Controlled fission reaction
Uncontrolled fission reaction

The blue colour of water in the sea. What is the reason behind the phenomenon?

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Refraction of the blue light by the impurities in sea water
Scattering of blue light by water molecules
Refraction of blue sky by sea water
Absorption of other colours except the blue colour by water molecules

Biogas mainly consists of

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Carbon dioxide and hydrogen
Hydrogen and methane
Carbon dioxide and methane
Hydrogen and oxygen

The difference between a nuclear reactor and atomic bomb is that

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No chain reaction takes place in nuclear reactor while in the atomic bomb there is a chain reaction
The chain reaction in nuclear reactor is controlled
The chain reaction in nuclear reactor is not controlled
No chain reaction takes place in atomic bomb while it takes place in nuclear reactor

H2O is liquid and H2S is a gas because

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Oxygen forms stronger hydrogen level than sulphur
Oxygen is less electronegative than sulphur
Atomic radius of oxygen is less than that of sulphur
Atomic radius of oxygen is greater than that of sulphur

What is “ Kiss of death” ?

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A flower whose smell was the basis of a discovery on smell that led to award of 2004 Nobel Prize in Medicine.
A chemical whose discovery ultimately won the scientists the 2004 Nobel Prize in Chemistry
A good wine flavour working on which scientist won the 2004 Nobel Prize in Chemistry
A network in brain associated with smell whose discovery led the scientists win the 2004 Nobel Prize in Physiology and Medicine

The inexhaustible source of energy of the stars is due to

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Conversion of hydrogen to helium
Conversion of helium to hydrogen
Decay of radioactive elements
Excess of oxygen that helps burning and release of energy

Hydrofluoric acid is not kept in glass bottles because it reacts with

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Visible light
Sodium oxide of glass
Aluminium oxide of glass
Silicon dioxide of glass

Which one of the following pairs is correctly matched?

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Silver iodide — Horn silver
Silver chloride — Artificial rain
Zinc phosphide — Rat poison
Zinc sulphide — Philosopher’s wool

While tinning of brass utensils, the ammonium chloride powder used to clean the hot utensil produces fumes of

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Ammonia
Carbon monoxide
Carbon monoxide
Ammonia and hydrochloric acid

When soggy biscuits are kept inside the fridge for sometime they become crisp because

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Cooling releases extra moisture
Humidity inside the fridge is low and extra moisture is absorbed
Humidity inside the fridge is high and extra moisture is absorbed
Pressure inside the fridge is high and helps in releasing extra moisture

A sample of chloroform before using as an anaesthetic, is tested by

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Fehling’s solution
Ammonical cuprous chloride
Ammonical silver nitrate solution
Silver nitrate solution after boiling with alcoholic KOH

Which one of the following statements is not true about cosmic rays?

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They are electromagnetic waves
They have very short wavelength
They are made of highly energetic charged particles
They originated from the sun

History Exam : Question 1 of 25