. April 2018

Wave Optics: Diffraction

Q- You have obtained a diffraction pattern on a distant screen from a plane diffraction grating consisting of alternate transparent and opaque lines with widths a and b respectively. How will the pattern be affected if the widths a and b are interchanged? Consider

(a) Change in intensity

(b) Absen…

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NLM Elastic Collision

Q- Suppose that a particle of mass m1 approaches a stationary mass m2 and that m2 >> m1.

(a) Describe the velocity of m2 after an elastic collision.

(b) What is the approximate momentum of m1 after collision?


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Ray Optics: Lens

Q- An object 5 cm high is located 73 cm from a converging lens of focal length f1 = 45 cm. A second converging lens of focal length f2 is located 178 cm from the first lens. An image of the object is to be formed on a screen 200 cm from the second lens. What must be the focal length f2 of the second…

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(On request - Krupa)

Q- A heavy uniform chain lies on horizontal table top If coefficient of friction between the chain and the table top is 0.25 then what is the maximum fraction of the length of the chain that can hang over the edge of the table? 


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Sound Waves: Interference

Q- Two in-phase loudspeakers are located at (x, y) coordinates (-2.5 m, +2.0 m) and (-2.5 m, -2.0 m). They emit identical sound waves with a 1.6 m wavelength and amplitude a. Determine the amplitude A of the sound at the five positions on the y-axis (x = 0) with the y values 0, 0.5 m, 1.0 m, 2.0 m.

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Thermal Physics

Q- Work is done on the water by a rotating paddle wheel, which is driven by two blocks falling at a constant speed. The temperature of the stirred water increases due to friction between the water and the paddles. If the energy lost in the bearings and through the walls is neglected, then the loss i…

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Optics: Angular Resolution

Q- If two point objects close together are to be seen as two distinct objects, the images must fall on the retina on two different cones that are not adjacent. That is, there must be an unactivated cone between them. Assume the separation of the cones is 0.8 µm. Model the eye as a uniform 2.2 cm dia…

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