The working principle of LED is based on:
A. Incandescence
B. Electroluminescence
C. Heating effect of current
D. Fluorescence
Answer: Option B
Solution (By JKSSB Mock Tests)
LED (Light Emitting Diode) works on electroluminescence: when electrons recombine with holes in a semiconductor junction, energy is released as photons. This is distinct from incandescence (heating filament, like bulbs), fluorescence (absorb UV, emit visible), or heating effect. Memory aid: 'LED = semiconductor light emission; no filament'. This modern application question tests knowledge of everyday physics, common in competitive exams. Always link device to underlying phenomenon: LED (electroluminescence), laser (stimulated emission), solar cell (photovoltaic effect).
No comments yet. Be the first to start the discussion!