Procedure pic 1 Data pic 2 Based on the data and the procedu

Procedure (pic 1)

Data (pic 2)

Based on the data and the procedure above please answer the following two questions in the pic below about the grating spectrometer lab

Much thanks ^^

122 Angular Scales Grating Telescope Collimator Figure 19.3 An overhead view of the parts of the diffraction grating spectrometer PROCEDURE 1. Position the telescope so that it is perpendicular to the grating. Move it until you see a bright white band in the cross hairs. Impo choose one of the windows and use it to measure all of your angles. That is, make sure you always read the angle from the same goniometer angular scale of the apparatus! 2. Swing the telescope to the right until you observe the separated colors of the spectrum. Set the telescope cross hairs to the first mercury line to the right, Record its color. Then read the angle from your chosen goniometer angular scale and record the angle in your data table as pi. 4. Swing the telescope to find the same color line to the left. Read the angle from your chosen goniometer angular scale and record the angle in your data table as p 5. Repeat procedures 3 through 5 for the other colors. Take care that you are observing the first line of each color on either side. 6. Now measure the angles (eft and right for the second appearance of just the green and yellow lines. Record the angles as p2 and

Solution

solution:

1)grating spectrometet is instrument which is used to calculate wavelength of source of light as well wavelength for variuos color.

2)first of all by rotating telescope we measure angle for first maxima for each color and noted phi 1 and phi 1\'

and mean value of difference for each measurement gives as angle twice the deflection at slit of grtaing spectrometer and hence deflection is given by

2*phi=(Phi1-Phi1\')

it gives value of deflection as phi=(phi1-phi1\')/2

hence value of deflection from reading for various color are

for green,phi=89

for violet,phi=88

for blue violet,phi=88.5

for yellow,phi=88.5

4)here we take green light as standard for finding number of lines per unit length of grating and this value used to calculate wavelength for variuos color

for green wavelength is 5461 A

hence by formula we get

sin(phi)/n*wavelength=N

for first maxima,n=1

N=1830887.558

for violet light

phi=88

wavelength v=sin(88)/N=5458.5 A

for blue violet light

phi=88.5

wavelength b=sin88.5/N=5459.9 A

for yellow light

phi=88.5

wavelength y=sin(88.5)/N=5459.9A

4)where standard value wavelength gives as error in wavelength as follows

for violet

standard wavelength=4078 A

obtained wavelength=5458.5

percentage error=(obtained wavelength-std. wavelength/standard wavelength)*100=33.85%

for blue violet light

standard wavelength=4916 A

obtained wavelength=5459.9

percentage error=(obtained wavelength-std. wavelength/standard wavelength)*100=11.06%

for yellow light

standard wavelength=5770 A

obtained wavelength=5459.9 A

percentage error=(obtained wavelength-std. wavelength/standard wavelength)*100=-5.374%