Go Back   Physics Help Forum > High School and Pre-University Physics Help > Light and Optics

Light and Optics Light and Optics Physics Help Forum

Reply
 
LinkBack Thread Tools Display Modes
Old Sep 12th 2014, 10:23 AM   #1
Senior Member
 
Join Date: Jun 2014
Posts: 306
value of θ of first minimum

please refer to the photo , i am having problem with part (a)
my working is d sin θ = λ
sin θ = λ /d , where d is the seperation between slits.. by plug in value of λ = 580x10^-9 and d =0.7X 10^-6 , i have my θ = 47 ° , the ans given is 56°
why am i wrong?
Attached Thumbnails
value of θ of first minimum-img_20140912_163017-1-.jpg   value of θ of first minimum-img_20140912_162943-1-.jpg  

Last edited by ling233; Sep 16th 2014 at 03:43 AM.
ling233 is offline   Reply With Quote
Old Sep 16th 2014, 03:45 AM   #2
Senior Member
 
Join Date: Jun 2014
Posts: 306
Unhappy

i know i shouldnt bump my own thread here. but i have posted this this sevreal days ago. yet it is not answered. i am quite disappointed.
can someone try to reply?
ling233 is offline   Reply With Quote
Old Sep 23rd 2014, 02:13 AM   #3
Junior Member
 
Join Date: Sep 2014
Posts: 12
Diffraction angle

Originally Posted by ling233 View Post
please refer to the photo , i am having problem with part (a)
my working is d sin θ = λ
sin θ = λ /d , where d is the seperation between slits.. by plug in value of λ = 580x10^-9 and d =0.7X 10^-6 , i have my θ = 47 ° , the ans given is 56°
why am i wrong?
Hi,

a) In the picture the wavelength of light is given as 580 mm. It must be 580 nm.

b) You are calculating the first maximum with the formula

sin θ = λ /d

which in general is

sin θ = m λ /d.

Giving

λ = 580x10^-9 and d =0.7X 10^-6

sin θ = 580 x 10^-9 / 0.7 x 10^-6 = 0.83 and

arcsin (0.83) = 56°.

c) I do not understand how the book gives the 16°, 34° and the 56° for the first, second and the third orders. By the way the a) part of the question does not ask the first maximum but the first minumum!
__________________
Örsan Yüksek

Last edited by orsanyuksek; Sep 25th 2014 at 12:28 AM.
orsanyuksek is offline   Reply With Quote
Reply

  Physics Help Forum > High School and Pre-University Physics Help > Light and Optics

Tags
θ, minimum



Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
minimum force needed ling233 Kinematics and Dynamics 1 Oct 12th 2015 01:36 PM
Finding minimum values for problems hooperoo Kinematics and Dynamics 2 Aug 3rd 2013 03:28 PM
Finding minimum speed njuice8 Kinematics and Dynamics 2 Feb 19th 2013 03:03 AM
Minimum angle of resolution Elemental Advanced Optics 0 Aug 14th 2009 09:06 AM
Minimum power asi123 Energy and Work 1 Oct 24th 2008 06:57 PM


Facebook Twitter Google+ RSS Feed