Which of the following is used for removing air bubbles from glass during its manufacture?
1.Arsenous oxide
2.Potassium carbonate
3.Soda ash
4.Feldspar
For galvanizing iron which of the following metals is used?
1.Aluminium
2.Copper
3.Lead
4.Zinc
For safety, the fuse wire used in the mains for household supply of electricity must be made of metal having
1.Low melting point
2.High resistance
3.High melting point
4.Low specific heat
In a normal human body, the total number of red blood cells is
1.15 trillion
2.20 trillion
3.25 trillion
4.30 trillion
In vulcanization, natural rubber is heated with
1.Carbon
2.Silicon
3.Sulphur
4.Phosphorous
Oxygen was independently discovered by
1.Rutherford
2.William Ramsay
3.Joseph Priestley
4.Neils Bohr
Permanent hardness of water may be removed by the addition of
1.Sodium carbonate
2.Alum
3.Potassium permanganate
4.Lime
Quartz crystals normally used in quartz clocks etc. is chemically
1.Silicon dioxide
2.Germanium oxide
3.A mixture of germanium oxide and silicon dioxide
4.Sodium silicate
The element of an electric stove made
1.Copper
2.Invar
3.Magnalium
4.Nicrome
Until Victorian times, chocolate was thought of as a drink. When did the first chocolate bar appear?
1.1828
2.1831
3.1825
4.There is no sure date