heya meta...give me the practical experiment of Physics class 12th✍️✍️
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name of experiment is....✌️✌️
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TO DETERMINE THE ANGLE OF MINIMUM DEVIATION FORNA GIVEN PRISM BY PLOTTING A GRAPH.❤️❤️
Answers
Aim
To determine angle of minimum deviation for a given prism by plotting a graph between angle of incidence and the angle of deviation.
Apparatus
Drawing board, a white sheet of paper, prism, drawing pins, pencil, half-metre scale, office pins, graph paper and a protractor.
Theory
The refractive index in) of the material of the prism is given by
to-determine-angle-of-minimum-deviation-for-a-given-prism-by-plotting-a-graph-between-angle-of-incidence-and-the-angle-of-deviation-1
where, Dm angle of minimum deviation and A angle of the prism.
Procedure
Fix a white sheet of paper on the drawing board with the help of drawing pins or tape.
Draw a straight line XX’ parallel to the length of the paper nearly in the middle of the paper.
Mark points Q1, Q2, Q3,… on the straight line XX’ at suitable distances of about 5 cm.
Draw normals N1Q1, N2Q2, N3Q3,… on points Q1, Q2, Q3,… as shown in diagram.
Draw straight lines R1Q1, R2Q2, R3Q3,… making angles of 35°, 40°, … 60° (write value of the angles on the paper) respectively with the normals.
Mark one comer of the prism as A and take it as the edge of the prism for all the observations.
Put it prism with its refracting face AB in the line XX’ and point Q1 in the middle of AB.
Mark the boundary of the prism.
Fix two or more office pin P1 and P2 vertically on the line R1Q1. The distance between the pins should be 10 mm or more.
Look the images of point P1 and P2 through face AC.
Close your left eye and bring open right eye in line with the two images.
Fix two office pins P3 and P4 vertically, and 10 cm apart such that the open right eye sees pins P4 and P3 and images of P2 and P1 in one straight line.
Remove pins P3 and P4 and encircle their pricks on the paper.
Repeat steps 7 to 13 with points Q2, Q3,… for i = 40°,…, 60°.
To measure D in different cases
Draw straight lines through points P4 and P3 (pin pricks) to obtain emergent rays S1T1,S2T2,S3T3,……
Produce T1S1, T2S2, T3S3, … inward in the boundary of the prism to meet produced incident rays R1Q1, R2Q2, R3Q3,… at points F1, F2, F3,…
Measure angles K1F1S1,K2F2S2,K3F3S3,…….. These give angle of deviation D1,D2,D3,….
Write values of these angles on the paper.
To measure A
Measure angle BAC in the boundary of the prism. This gives angle A.
Record your observations.
Observations
Angle of prism ‘A’ =……
to-determine-angle-of-minimum-deviation-for-a-given-prism-by-plotting-a-graph-between-angle-of-incidence-and-the-angle-of-deviation-3 (2)
Calculations
Plot a graph between angle of incidence ∠i and angle of deviation ∠D by taking ∠i along X-axis and ∠D along Y-axis. From this graph, find the value of single of minimum deviation Dm corresponding to the lowest point of the graph.
to-determine-angle-of-minimum-deviation-for-a-given-prism-by-plotting-a-graph-between-angle-of-incidence-and-the-angle-of-deviation-4
to-determine-angle-of-minimum-deviation-for-a-given-prism-by-plotting-a-graph-between-angle-of-incidence-and-the-angle-of-deviation-5
Result
i-D graph indicates that as the angle of incidence (i) increases, the angle of deviation (D) first decreases, attains a minimum value (Dm ) and then starts increasing for further increase in angle of incidence.
Angle of minimum deviation, Dm = ……..
Refractive index of the material of the prism, n = ……….
Precautions
The angle of incidence should lie between 35°-60°.
The pins should be fixed vertical.
The distance between the two pins should not be less than 10 mm
Arrow heads should be marked to represent the incident and emergent rays.
The same angle of prism should be used for all the observations.
Sources of error
Pin pricks may be thick.
Measurement of angles may be wrong.
Aim
To determine angle of minimum deviation for a given prism by plotting a graph between angle of incidence and the angle of deviation.
Apparatus
Drawing board, a white sheet of paper, prism, drawing pins, pencil, half-metre scale, office pins, graph paper and a protractor.
Theory
The refractive index in) of the material of the prism is given by
to-determine-angle-of-minimum-deviation-for-a-given-prism-by-plotting-a-graph-between-angle-of-incidence-and-the-angle-of-deviation-1
where, Dm angle of minimum deviation and A angle of the prism.
Diagram
to-determine-angle-of-minimum-deviation-for-a-given-prism-by-plotting-a-graph-between-angle-of-incidence-and-the-angle-of-deviation-2
Procedure
Fix a white sheet of paper on the drawing board with the help of drawing pins or tape.
Draw a straight line XX’ parallel to the length of the paper nearly in the middle of the paper.
Mark points Q1, Q2, Q3,… on the straight line XX’ at suitable distances of about 5 cm.
Draw normals N1Q1, N2Q2, N3Q3,… on points Q1, Q2, Q3,… as shown in diagram.
Draw straight lines R1Q1, R2Q2, R3Q3,… making angles of 35°, 40°, … 60° (write value of the angles on the paper) respectively with the normals.
Mark one comer of the prism as A and take it as the edge of the prism for all the observations.
Put it prism with its refracting face AB in the line XX’ and point Q1 in the middle of AB.
Mark the boundary of the prism.
Fix two or more office pin P1 and P2 vertically on the line R1Q1. The distance between the pins should be 10 mm or more.
Look the images of point P1 and P2 through face AC.
Close your left eye and bring open right eye in line with the two images.
Fix two office pins P3 and P4 vertically, and 10 cm apart such that the open right eye sees pins P4 and P3 and images of P2 and P1 in one straight line.
Remove pins P3 and P4 and encircle their pricks on the paper.
Repeat steps 7 to 13 with points Q2, Q3,… for i = 40°,…, 60°.
To measure D in different cases
Draw straight lines through points P4 and P3 (pin pricks) to obtain emergent rays S1T1,S2T2,S3T3,……
Produce T1S1, T2S2, T3S3, … inward in the boundary of the prism to meet produced incident rays R1Q1, R2Q2, R3Q3,… at points F1, F2, F3,…
Measure angles K1F1S1,K2F2S2,K3F3S3,…….. These give angle of deviation D1,D2,D3,….
Write values of these angles on the paper.
To measure A
Measure angle BAC in the boundary of the prism. This gives angle A.
Record your observations.
Observations
Angle of prism ‘A’ =……
to-determine-angle-of-minimum-deviation-for-a-given-prism-by-plotting-a-graph-between-angle-of-incidence-and-the-angle-of-deviation-3 (2)
Calculations
Plot a graph between angle of incidence ∠i and angle of deviation ∠D by taking ∠i along X-axis and ∠D along Y-axis. From this graph, find the value of single of minimum deviation Dm corresponding to the lowest point of the graph.
to-determine-angle-of-minimum-deviation-for-a-given-prism-by-plotting-a-graph-between-angle-of-incidence-and-the-angle-of-deviation-4
to-determine-angle-of-minimum-deviation-for-a-given-prism-by-plotting-a-graph-between-angle-of-incidence-and-the-angle-of-deviation-5
Result
i-D graph indicates that as the angle of incidence (i) increases, the angle of deviation (D) first decreases, attains a minimum value (Dm ) and then starts increasing for further increase in angle of incidence.
Angle of minimum deviation, Dm = ……..
Refractive index of the material of the prism, n = ……….
Precautions
The angle of incidence should lie between 35°-60°.
The pins should be fixed vertical.
The distance between the two pins should not be less than 10 mm
Arrow heads should be marked to represent the incident and emergent rays.
The same angle of prism should be used for all the observations.
Sources of error
Pin pricks may be thick.
Measurement of angles may be wrong.