Cathode Rays, Thomson's Experiment & Gas Discharge
In the phenomenon of electric discharge through gases at low pressure, the coloured glow in the tube appears as a result of
Show answer and solution
Answer: (a)
- At low pressure, cathode-ray electrons are accelerated to high speed by the large field.
- They collide with gas atoms, excite them, and the atoms emit light on de-excitation.
- So the glow is due to collisions of charged particles from the cathode with gas atoms: answer (a).