SELECT * FROM question_mgmt as q WHERE id=2740 AND status=1 SELECT id,question_no,question,chapter FROM question_mgmt as q WHERE courseId=3 AND subId=8 AND chapterId=124 and ex_no='1' AND status=1 ORDER BY CAST(question_no AS UNSIGNED)

Question:

 Estimate the distance for which ray optics is good approximation for an aperture of 4 mm and wavelength 400 nm.

Answer:

Fresnel’s distance (Zf ) is the distance for which the ray optics is a good approximation. It is given by the relation, Zf = a2/λ

Where,

Aperture width, a = 4 mm = 4 ×10 -3 m

Wavelength of light, λ = 400 nm = 400 × 10 -9 m

Zf = (4x10-3)2/400x10-9 = 40 m

Therefore, the distance for which the ray optics is a good approximation is 40 m.


< Previous Question

Next Question >

SELECT ex_no,question,question_no,id,chapter FROM question_mgmt as q WHERE courseId='3' AND subId='8' AND ex_no!=0 AND status=1 and id!=2740 ORDER BY views desc, last_viewed_on desc limit 0,10

  • Popular questions of class 12 Physics

SELECT ex_no,question,question_no,id,chapter FROM question_mgmt as q WHERE courseId='3' AND subId='8' AND ex_no!=0 AND status=1 and id!=2740 ORDER BY last_viewed_on desc limit 0,10

  • Recently Viewed Questions of Class 12 Physics

Comments

  • Answered by Ekta Mehta
  • 4 months ago

Taking Screenshots on your Samsung Galaxy M31s is very easy and quick.

  • Answered by Ekta Mehta
  • 4 months ago

Taking Screenshots on your Samsung Galaxy M31s is very easy and quick.

  • Answered by Ekta Mehta
  • 4 months ago

Taking Screenshots on your Samsung Galaxy M31s is very easy and quick.

Comment(s) on this Question


Important links

Quick Links

Resources

Support