Which compressor is usually used in AC?
A). Centrifugal
B). Rotary
C). Reciprocating
D). Axial
RADAR is used for:
A). locating submerged submarines.
B). receiving a signals in a radio receiver.
C). locating geostationary satellites.
D). detecting and locating the position of objects such as Aeroplanes.
Materials for rain-proof coats and tents owe their water-proof properties to
A). surface tension
B). viscosity
C). specific gravity
D). elasticity
Point A is at a lower electrical potential than point B. An electron between them on the line joining them will
A). Move towards A
B). Move towards B
C). Move at right angles to the line joining A and B
D). Remain at rest
On a rainy day, small oil films on water show brilliant colours. This is due to
A). dispersion
B). interference
C). diffraction
D). polarization