AIIMS 2013
- Exam
- AIIMS
- Year
- 2013
- Subject
- Physics
- Chapter
- Electromagnetic Waves
AIIMS 2013 · Physics · Electromagnetic Waves
Assertion : A laser beam of 0.2 ~W power can drill holes through a...
Assertion : A laser beam of power can drill holes through a metal sheet, whereas a torch-light cannot.
Reason : The frequency of laser light is much higher than that of torch light.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion.
- BIf both assertion and reason are true but reason is not the correct explanation of assertion.
- CIf assertion is true but reason is false.
- DIf both assertion and reason are false.
Correct answer
C. If assertion is true but reason is false.
Step-by-step solution
A laser is a highly monochromatic and nearperfect parallel beam of light, due to which the beam can be focussed by a converging lens to a very small spot. As the intensity of the beam is too high, it can drill holes through a metal sheet even if the power is . But even a torch-light of power cannot drill holes in such a metal sheet, because the light is less intense and the beam is not parallel.