Question

5. A 2.0 cm high object is placed 10 cm in front of a lens. An upright image is formed by the lens and is located 20 cm from the lens. (a) (2 pts.) Is the image real or virtual? Explain. (b) (2 pts.) Calculate the focal length of the lens. (c) (2 pts.) Is the lens a converging or diverging lens, explain. (d) (2 pts.) Calculate the magnification of the image. (e) (2 pts.) Calculate the height of the image. 6. Two coherent wavelengths of light are incident on a double slit, one of the wavelengths corresponds to blue light of 460 nm and the other is unknown. The slit separation is 0.007 mm. The second-order bright fringe of the blue light falls at the same angle as the first order light of the other wavelength. (a) (3 pts.) Determine the unknown wavelength. (b) (2 pts.) Determine the number of fringes of these two wavelengths visible to one side of the zeroth order bright fringe. (c) (3 pts.) Suppose a screen were placed 30 cm from the slits. How large of a screen would be required to fit all of the fringes from part (b)? (d) (2 pts.) Describe how the appearance of the fringes would change if a grating of equal slit separation were used in place of the double slits. Include any changes to fringe separation or brightness in your description Attach File Browse My Computer

Answer 1

5u=-10em, 10 = + 20em; if (f = focus of the rens Play now, magnefication (m) - na = 20 = -2 as here an, hore love? sign present, so, the image is not reali S tate Dr, Loto - on ta 6.67em. the treal length is f = 16.67 cm.)
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20 @ The lens is converging, as here focal length is itve in sign, sone know for fa tve, lens will be I converging (d The magnifications of the image in, man Os may = 20 magnification (m) = [-2] Cel Obseet soms dista. (e) object Length (6)= 2em; Let 'I' be the image length 5 -2 or, I = -2 X2 S-4 I Height of length is Is A em F10 :-2
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