Question

Problem 17.21 - Enhanced - with Feedback A diffraction grating with 620 lines per mm is illuminated with light of wavelength 520 nm A very wide viewing screen is 2.0 m behind the grating Part A What is the distance between the two m=1 fringes? Express your answer in meters. ΡΙ ΑΣφ ? Ay = n Submit Request Answer Part B How many bright fringes can be seen on the screen? Express your answer as an integer. Η ΑΣφ fringe(s)

Answer 1

There are 620 lines per mm. So, slit seperation is b= 1 mm 620 эр 1x 10 m b=162x10tm 620 Wave length of light is d=520x108m Part A D=2m o Jo VI! Ilir For 1st maseeman Ibseno=.1x) AY D A

520x109 seno= 11 b (62) x 10-4 sino = 0.3224 citanos 0.3224 Ji-(0.32243² > tano = 0.340586= Yr > Yo = DX0.340586 =2x0:340586 m Si = 0.681172 m Lisy = y, ty, = 24, = 2x0.681172m > 4y= 1.362m Part B. For mith bright fringe bsino=my bsino a seno al m= x mc les x 10*4) 520x16 » m 2 3.1

Maximum value of m is 3. So in addition to central masina there will be 3 fringes on each side. So total number of bright fringes will be F.