A stick of $1 \,m$ is moving with velocity of $2.7 \times {10^8}m{s^{ - 1}}$. ........... $m$ is the apparent length of the stick $(c = 3 \times {10^8}m{s^{ - 1}})$
$10$
$0.22$
$0.44$
$2.4 $
Particle nature and wave nature of electromagnetic waves and electrons can be shown by
Which one of the following devices makes use of the electrons to strike certain substances to produce fluorescence
Who invented $X-$ rays?
Explain emission of electron from metal. Define work function. Write its unit, work function of metal depend on which factors ?
When the speed of electrons increases, then the value of its specific charge