(a)What is the cross product of two vectors? Why the cross product is called pseudo vector? [5]
(b)What is divergence of vector field? What is its physical significance? [5]
(c)What is line integral? Under what condition it is used to calculate the work done. [5]
(d)Consider three vectors: A=−3i+3j+2k B=-2i-4j+2k and Ĉ =2i+3j+1k Find A · (B×C) Find A × (B×C) [5]
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Q. 3
(a)What do you mean by circular motion? What is centrifugal force? Explain your answer by taking an example from daily life. [5]
(b)What is projectile motion? Why a cricket player lowers his hand while catching a ball? [7]
(c)What do you mean by work done by the system and work done on the system? Explain by taking an example of each. [5]
(d)A batsman hits a cricket ball at an angle with respect to the horizontal. The ball would strike the ground at 60m from the batsman if it is not stopped. But a fielder at a distance 55 m catches the ball at a height of 1.5 m. Calculate the angle of projection and the velocity of projection. [3]
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Q. 4
(a)What do you mean by phase and group velocity? Derive a relation between a group and phase velocity. [7]
(b)What is superposition of waves? Show that the standing waves are produced by the superposition of two waves of equal amplitudes moving in opposite direction. [5]
(c)A medium is disturbed by an oscillation described by, Y = 3.0cm sin(πx/10cm) cos (50πt) Determine the amplitude, frequency, wavelength, speed and direction of the component waves whose superposition produces this result. [3]
(d)If light of λ = 660nm has wave train 20λ, what is its coherence length and coherence time? [3]
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Q. 5
(a)What is unique about light from a laser source, and why should you never look directly into a laser beam? Explain briefly. [5]
(b)What is plasma? What do you mean by plasma frequency? Briefly discuss. [5]
(c)How the blue laser is useful in storing large amount of data on a CD as compared to red laser? [5]
(d)For the He-Ne laser at 2m and 4m distances from the laser, the output beam spot diameters are 2 mm and 3 mm. Calculate the angle of divergence. [5]
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Q. 6
(a)What is viscosity? Discuss effect of temperature on the viscosity of liquids and gases. [6]
(b)Differentiate between streamline and turbulent flow and establish equation of continuity. [4]
(c)Explain why the level of mercury is down in capillary when placed in container of mercury, while it is up in the capillary in case of water? [6]
(d)A garden hose has an inside diameter of 2 cm and water flows through it is at 3 m/s. What nozzle diameter is required for the water to emerge at 10 m/s? At what rate does the water leave the nozzle? [4]
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Q. 7
(a)What do you understand by classical statistical mechanics and quantum statistical mechanics? [6]
(b)Differentiate between Fermi-Dirac, Bose-Einstein and Maxwell-Boltzmann's statistics. [6]
(c)What is equipartition of energy? Explain. [5]
(d)A 0.5m³ vessal is filled with air at atmospheric pressure. The air is churned by a paddel wheel attached to a shaft 0.1m in diameter, rotating at a speed of 1800 rpm. A force of 5.0N acts on the rim of the shaft. What would be the pressure in the vessel after 10 sec of operation [3]
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Q. 8
Write notes on any FOUR of the following:
(a)Polarization of light and its application in determining specific rotation of a liquid. [5]
The 2017 CSS Physics paper set by the FPSC. Question wording only; questions marked “Not yet checked” have not been compared with the official paper yet.
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