FOLLOW US ON TWITTER
SHARE THIS PAGE ON FACEBOOK, TWITTER, WHATSAPP ... USING THE BUTTONS ON THE LEFT


YOUR PARTICIPATION FOR THE GROWTH OF PHYSICS REFERENCE BLOG

Sunday, November 17, 2019

A diffraction grating experiment is set up using yellow light of wavelength 600 nm.


Question 27
A diffraction grating experiment is set up using yellow light of wavelength 600 nm. The grating has a slit separation of 2.00 μm.



What is the angular separation (θ2 – θ1) between the first and second order maxima of the yellow light?
A 17.5°                        B 19.4°                        C 36.9°                        D 54.3°





Reference: Past Exam Paper – November 2014 Paper 11 & 12 Q27 & March 2019 Paper 12 Q29

Note: For March 2019 Paper 12 Q29: 'orange light' instead of 'yellow light'




Solution:
Answer: B.

For a diffraction grating: d sinθ = nλ

Wavelength λ = 600nm = 600×10-9 m
Slit separation d = 2.00 μm = 2.0×10-6 m

Angle θn = sin-1 (nλ / d)
When n = 1, θ1 = sin-1 ({600×10-9} / {2.0×10-6}) = 17.458°
When n = 2, θ2 = sin-1 (2 × {600×10-9} / {2.0×10-6}) = 36.870°

Angular separation (θ2 – θ1) = 36.870 – 17.458 = 19.4°

No comments:

Post a Comment

If it's a past exam question, do not include links to the paper. Only the reference.
Comments will only be published after moderation

Currently Viewing: Physics Reference | A diffraction grating experiment is set up using yellow light of wavelength 600 nm.