Experiment No.1 Aim: To find the refractive index and Cauchy’s constants of a prism using spectrometer. The Prism Spectrometer (Version 4.0, 1/7/2002) 3 δ Angle of minimum deviation apex angleα min δ > δ Angle of deviation greater than minimum min There exist extensive tables of the line spectra of many elements. 2: Set-up and path of rays in the spectrometer. To determine angle of minimum deviation for a given prism by plotting a graph between angle of incidence and angle of deviation. THE PRISM SPECTROMETER Michigan State University. Figure 8.8 Determination of Angles of Minimum Deviation Next, set the prism to obtain the angles of minimum deviation. Experiment No.1 Object: To determine the refractive index of a prism by using a spectrometer. Locate the prism in such a position that the vertex of the refracting angle is toward the collimator. The readings of the verniers are again noted. The preliminary adjustments of the telescope, collimator and the prism table of the spectrometer are made.
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Read the … Experiment 1 (Lab period 1) Spectrophotometry: Absorption spectra and the use of ... a spectrometer and a photometer. Fix two or more office pin P 1 and P 2 vertically on the line R 1 Q 1. 2. 6.Find the di erence between the direct ray readings and deviated readings. The distance between the pins should be 10 mm or more. 2 Dispersive Power of Prism Experiment No. FORMULA: The dispersive power of the prism is given by b g av 1 w Where, 2 b g av sin 2 sin 2 B b A D A sin 2 sin 2 g G A D A A = angle of the prism D The prism is removed. The average value of minimum deviation D is calculated. �if�̈́;8�F�:��?˅U�y��
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���^g��n�q���La2T�H,�BR�=j�~+݀̎kŮE>A�':��$��?�t9i����"M You can change your cookie settings at any time. Turn the telescope parallel to collimator, and note the direct ray readings. In this session you will have: Gained a proficiency in the reading of vernier scales Carefully replace the prism table on the spectrometer. Prism Spectrometer. The difference in the readings of the same vernier gives the angle of minimum deviation. The refracting edge of the prism placed facing the collimator. This angle is called angle of minimum deviation (D). (iv) The prism should be placed in minimum-deviation position with respect to the mean ray and the refracting edge of the prism should be parallel to the slit. This is because the prism refractive index varies with wavelength (the property known as dispersion) and so you will also be able to measure this property as well. The prism must remain in fixed position for both readings. L-6 SPECTROMETER Instructor's Notes. This is because the prism refractive index varies with wavelength (the property known as dispersion) and so you will also be able to measure this property as well. Turn the telescope parallel to collimator, and note the direct ray readings. We use cookies to ensure that we give you the best experience on our website. ), a portion of the light is transmitted and the other portion is reflected. Sometimes a diffraction grating is used in place of the prism for studying optical spectra. 3. 2 Object: To find the wavelength of white light with the help of a plane transmission diffraction grating. Each wavelength will be affected slightly differently which is why when you shoot white light at the prism you get a rainbow pattern on the other side. The glass-prism spectrometer is suitable for measuring ray deviations and refractive indices. Mark the boundary of the prism. The photometer consists of a photoelectric tube In this video we will study about spectrometer, Calculation of least count and also observe readings. Theory The spectrometer is an instrument for analyzing the spectra of radiations. Determination of the refractive index of the material of the prism . Experiment with the glas prism Fig. Fill in the cells for the spectrometer readings y and perform fitting. CBSE class 12th Physics practical file readings. The vertical cross-wire is made to coincide with the direct image of the slit. 3. In the first part of the experiment, you will be using the known spectrum of mercury to calibrate your prism spectrometer. Level the prism table, telescope and collimator with spirit level such that telescope axis and collimator, axis intersect the principal vertical axis of the spectrometer. Object: - To determine the dispersive power of the material of the prism using mercury light with the help of a spectrometer. You should observe the lines in the sodium spectrum. Formula : The dispersive power of the material of a prism is given by R 1) Y v Where V Refractive index of the material of a prism for extreme violet colour Refractive index of the material of the prism is determined by using eq. 2. A prism refracts the light into a single spectrum, whereas the diffraction grating divides the available light into several spectra. Clamp the prism table in place. Be careful when adjusting the spectrum tubes or the power supplies. (12) 5 Spectrometer Experiment 112-8 Now, using the positioning jig, rotate the prism on the spectrometer table so that it is ori-ented as shown in figure 8.8A. Formula used: (i) The refractive index of the material of the prism is given by the formula:-µ 2 sin 2 sin A A m Where A= Angle of prism δm=Angle of minimum deviation. PHYSICS PRACTICAL HIGHER SECONDARY - SECOND YEAR S.NO DATE NAME OF THE EXPERIMENT PAGE 1 Spectrometer - Prism 2 Spectrometer - Grating 3 Metre Bridge 4 Potentiometer 5 Tangent Galvanometer 6 Sonometer 7 PN - junction diode and Zener Diode 8 NPN Transistor - Part-1 9 NPN Transistor - Part-2 10 Operational Amplifier - Inverting This experiment can be performed in one three hour lab period if part (1) of Experiment A is done by the instructor before class, and the students are instructed (by a demonstration) how to perform the prism table leveling. A prism can separate the wavelengths of incoming light due to the fact that it slows down the light and bends it. Swing the telescope around until the slit image, reflected from one prism face, is exactly on the crosshairs. EXPERIMENT-1 DISPERSIVE POWER OF A PRISM AIM: To determine the dispersive power of a material of prism using Spectrometer APPARATUS: Spectrometer, Prism, Mercury Vapor Lamp etc. this, measure the prism apex angle A as follows: 1. The exact process depends upon the refraction index of the prism. The prism should be placed off-center on the table, as shown, so that the reflected beams will not miss the telescope. Apparatus Required: Spectrometer, prism, mercury vapour lamp, spirit level and reading lens. Sometimes a diffraction grating is used in place of the prism for studying optical spectra. 1. 6. As a result, You can measure this minimum deviation directly for any ray that comprises a single wavelength of light (a monochromatic beam). Then the rays of different colours will be focussed on the screen at different points. The other portion is reflected ( Lab period 1 ) Spectrophotometry: Absorption spectra and the vernier readings R. 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