A tape recorder can be used both for recording and reproduction of sound with the help of
magnetic property of the tape
electrical property of the tape
chemical property of the tape
metallic property of the tape
TV set receives waves through
Receiver
Local antenna
Picture tube
Speaker
The wireless system was invented by
Marconi
Graham Bell
Edison
Newton
TV was invented by
James Watt
J.L.Biard
The electro magnetic waves was invented by
Marx Plank
Maxwell
Magnetic recording and reproduction are made by
electro magnets
permanent magnets
copper rods
graphite roads
Matter has
mass
volume
both mass and volume
only mass but not volume
J.J. Thomson discovered electron in
1892
1893
1864
1895
The velocity of electro magnetic waves.
3 lakh kilometers per second
5 lakh kilometers per second
4 lakh kilometers per second
1 lakh kilometers per second
A radio set receives electro magnetic waves and converts them in to sound waves back with the help of
antenna
receiver
speaker
tuner
