Science

Which is the instrument used to change Alternating Current (AC) into Direct Current(DC)?
Rectifier

What is the speed of sound in air?
340m/s

Which is the first instrument that man used?
Stone

Which is the alloy having the least metal?
Invar steel

What kind of lens is used in the eye defect, ‘Astigmatism”?
Cylindrical lens

Which is the gas filled in the electric bulb?
Argon

Which wave has the most wave length?
Radio wave

Who invented printing?
J.Guttenberg

Which light ray that has the capacity to cut metals?
Laser

What is the specific gravity of water?
1