Exercise 7

Question 46 :

Recently lead free petrol was introduced in our country because


A). they are not needed now as anti-knock agents
B). they tower the efficiency of the engine
C). they cause less pollution
D). to reduce the cost of petrol
Answer : Option C

Question 47 :

Rabindranath Tagore receive Nobel Prize in 1913 in the field of


A). physics
B). peace
C). literature
D). economy
Answer : Option C

Question 48 :

People who secretly indulge in anti-national or anti-government activities and help the enemy are called


A). Second column
B). Third column
C). Fourth column
D). Fifth column
Answer : Option D

Question 49 :

Sulphur is not present in


A). iron pyrites
B). gypsum
C). coal
D). chlorapatite
Answer : Option D

Question 50 :

Oxygen was independently discovered by


A). Rutherford
B). William Ramsay
C). Joseph Priestley
D). Neils Bohr
Answer : Option C

Explanation :

Oxygen was independently discovered by Carl Wilhelm Scheele, in Uppsala, in 1773 or earlier, and Joseph Priestley in Wiltshire, in 1774, but Priestley is often given priority because his work was published first.