81. Which of the following is an element?
A. Ruby
B. Sapphire
C. Emerald
D. Diamond
✅ The correct answer is option D.
General Science MCQs
82. Soda water contains
A. carbonic acid
B. sulphuric acid
C. carbon dioxide
D. nitrous acid
✅ The correct answer is option C.
83. Bell metal is an alloy of
A. nickel and copper
B. zinc and copper
C. brass and nickel
D. tin and copper
✅ The correct answer is option D.
84. The chemical (ethyl mercaptan) added to the otherwise odourless LPG cooking gas for imparting a detectable smell to the gas is a compound of
A. bromine
B. fluorine
C. chlorine
D. sulphur
✅ The correct answer is option D.
85. LPG consists of mainly
A. methane, ethane and hexane
B. ethane, hexane and nonane
C. methane, hexane and nonane
D. methane, butane and propane
✅ The correct answer is option D.
86. The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is
A. Argon
B. Xenon
C. Helium
D. Krypton
✅ The correct answer is option C.
87. Which of the following is in liquid form at room temperature?
A. Lithium
B. Sodium
C. Francium
D. Cerium
✅ The correct answer is option C.
88. Which of the following are the ingredients of gun metal?
A. Iron, Zinc, Titanium
B. Iron, tin
C. Iron, Brass, Tin
D. Copper, Tin
✅ The correct answer is option D.
89. Quartz crystals normally used in quartz clocks etc. is chemically
A. silicon dioxide
B. germanium oxide
C. a mixture of germanium oxide and silicon dioxide
D. sodium silicate
✅ The correct answer is option A.
90. Amalgams are
A. highly coloured alloys
B. alloys which contain mercury as one of the contents
C. alloys which have great resistance to abrasion
D. alloys which contain carbon
✅ The correct answer is option B.