The chemical (Ethyl Mercaptan) added to the odourless LPG cooking gas for imparting a detectable smell to the gas is a compound of:
(A) Sulphur

(B) Fluorine

(C) Chlorine

(D) Bromine

The inert gas which is substituted for nitrogen in the air, used by deep sea divers for breathing is--

(A) Helium

(B) Argon

(C) Krypton

(D) Xenon

The group of metals Fe, Co, Ni may be best called as:

(A) Alkaline metals

(B) Rare metals

(C) Main group metals

(D) Transition metals 

Amalgams are--

(A) Alloys which contain carbon

(B) Alloys which have great resistance to abrasion

(C) Alloys which contain mercury as one of the contents

(D) Highly coloured alloys

GPS contains of--

(A) 20 satellites

(B) 32 satellites

(C) 7 satellites

(D) 40 satellites

The property of a substance to absorb moisture from the air on exposure is called--

(A) Osmosis

(B) Dessication

(C) Efflorescence

(D) Deliquescence

Brass gets discoloured in air because of the presence of which of the following gases in air ?

(A) Carbon dioxide

(B) Oxygen

(C) Hydrogen sulphide

(D) Nitrogen

Quartz crystals normally used in quartz clock etc., is chemically-

(A) Sodium silicate

(B) Germanium oxide 

(C) Silicon dioxide

(D) a mixture of B and C

Bell metal is an alloy of

(A) brass and nickel

(B) zinc and copper

(C) tin and copper

(D)nickel and copper