MCQ
In a laser tube, all the photons:
- AHave same wavelength.
- BHave same energy.
- CMove in same direction.
- ✓Move with same speed.
✓
Answer
Correct option: D.
Move with same speed.
All the photons emitted in the laser move with the speed equal to the speed of light $(c = 3 \times 10^8m/s)$. Ideally, the light wave through the laser must be coherent, but in practical laser tubes, there is some deviation from the ideal result. Thus, the photons emitted by the laser have little variations in their wavelengths and energies as well as the directions, but the velocity of all the photons remains same.
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