At small distance from the earth the colour of lightning is
white
pink
violet
none of these
A gold leaf electroscope can
only detect the presence of charge
only test the kind of charge
only measure the charge
detect the presence of charge and test the kind of charge
The approximate duration of lightning is
105sec
10-5 sec
103sec
10-3 sec
Velocity of sound in air
320m|s
310M\s
330m|s
300m|s
The electrons which are in orbits close to the nucleus are called
bound electrons
valence electrons
free electrons
Generally connecting wires are made up of
Cu -Al
Ni -C
Tungsten
None of these
SI unit of current
volt
Joule
Ampere
