Fraunhoffer's lines: The central part (photosphere) of the sun is very hot and emits all possible wavelengths of the visible light. However, the outer part (chromospheres) consists of vapors of different components. When the light emitted from the photosphere passes through the chromospheres, certain wavelengths are real, Hence, in the spectrum of wave a large number of dark lines are seen called Fraunhoffer lines.

(i) The prominent waves in the yellow section of the visible spectrum were labeled as D-lines, those in blue part as F-lines and in red part as C-line.

(ii) From the study of Fraunhoffer's lines the presence of various elements in the sun's atmosphere can be verified.

(iii) In the event of a solar eclipse, black lines convert into bright. This is because of the reason that the presence of an opaque obstacle in between sun and earth cuts the light off from the central region (photo-sphere), while light from corner portion (chromospheres) is still being achieved. The bright lines seem exactly at the places where dark lines were present.

Spectrometer: A spectrometer is needed for creating pure spectrum of a source in laboratory and calculation of μ of material of prism and μ of a transparent liquid.

It has of three parts: Collimator which provides a parallel beam of light; Prism Table for holding the prism and Telescope for observing the spectrum and making measurements on it.

The telescope is first set for parallel rays and then collimator is set for parallel waves. When prism is fixed in minimum deviation position, the spectrum seen is real spectrum. Angle of prism (A) and angle of minimum deviation (δ_m) are measured and m of material of prism is calculated using prism formula. For μ of a transparent liquid, we consider a hollow prism with thin mirror sides. Fill it with the liquid and measure (δ_m) and A of liquid prism. μ Of liquid is calculated using prism formula.

Direct vision spectroscope: It is an instrument used to observe pure spectrum. It produces dispersion without deviation with the help of n crown prisms and (n - 1½ flint prisms alternately arranged in a tabular structure.

For no deviation n(μ-1)A = (n-1)(μ′ - 1)A′.

Email based Physics assignment help - homework help at Expertsmind

Are you searching physics expert for help with Fraunhoffer's lines questions?  Fraunhoffer's lines topic is not easier to learn without external help?  We at www.expertsmind.com offer finest service of Physics assignment help and physics homework help. Live tutors are available for 24x7 hours helping students in their Fraunhoffer's lines related problems. We provide step by step Fraunhoffer's lines question's answers with 100% plagiarism free content. We prepare quality content and notes for   Fraunhoffer's lines topic under physics theory and study material. These are avail for subscribed users and they can get advantages anytime.

Why Expertsmind for assignment help

1. Higher degree holder and experienced experts network
2. Punctuality and responsibility of work
3. Quality solution with 100% plagiarism free answers
4. Time on Delivery
5. Privacy of information and details
6. Excellence in solving physics queries in excels and word format.
7. Best tutoring assistance 24x7 hours