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Time : 3 Hours Note : (i) (ii) (iii) Maximum Marks : 100

This question paper consists of two Sections, viz., ‘A’ and ‘B’. All questions from Section ‘A’ are to be attempted. Section ‘B’ has got more than one option. Candidates are required to attempt questions from one option only. SECTION – A

1. To what physical quantity does the area under velocity-time graph represent ? 1 2. State the law of parallelogram of vectors. 3. Why are steel bridges declared unsafe after a long use ? 4. Sketch lines of force due to a small negatively charged sphere. 5. The closed end of a pipe is always a node. Why ? 1 1 6. Name the physical quantity which has the same value for the waves belonging to different parts of electromagnetic spectrum. 1 7. What is the lateral displacement of light beam incident normally on a glass slab? 1 8. Out of the following nuclides, write the pair of isotones : 1 3 He; 198 Hg; 12 C; 3 H; 197 Au; 12 C 2 1 80 6 79 6

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9. A ship of mass 3 x 107 kg initially at rest is pulled by a force of 5 x 104 N through a distance of 3 m. Assuming that the resistance due to water is negligible, calculate the speed of the ship. 2 10. Show that the value of acceleration due to gravity at a height h from the earth’s surface is the same as the value of acceleration due to gravity at a depth d(=2h), when h is very small compared to the radius of earth. 2 2, where 11. Check dimensionally the accuracy of the equation E=mgh + ½mv E is the total energy. 2 12. Three capacitors have their capacitance in the ratio of 2:3:6 when they are connected in series across a 100 V battery, the combination acquires a charge of 2mC. Calculate the capacitance of each capacitor. 2

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How do (a) pole strength and (b) magnetic moment of a bar magnet change, if it is cut into two identical pieces transverse to its length ? State Faraday’s laws of electrolysis. Define the term ‘Faraday constant’. Distinguish between ‘forced vibration and ‘resonant vibration’. Give one example of each. 2 2 2 Explain the effect on the interference pattern observed in Young’s double slit experiment, when the coherent sources are (a) infinitely close to each other and (b) far apart from each other. 2 What is nuclear force ? Mention its any three characteristic features. 2 An a.c. input signal of frequency 60 Hz is rectified by (a) half-wave and (b) full-wave rectifier. Draw the output waveform and write the output frequency in each case. 2 Identify logic gates P and Q in the given figure.

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Write down the truth table to find the output at y. 20. 3 What is an elastic collision ? In a one-dimensional elastic collision, when a body of mass (m1) with an initial velocity (u1) strikes another of mass (m2) which is at rest, find the expressions for the final velocities of the two bodies. Show that for the case of equal masses, they simply interchange their velocities. Give an example of such a type of collision. 3 The wheel of a car is completing 1200 rotations per minute. On pressing the accelerator of the car, the wheel makes 4500 rotations per minute in a time interval of 10 seconds. Calculate (a) angular acceleration and (b) number of rotations in 10 seconds. 3 State Pascal’s law of transmission of liquid pressure. With the help of a diagram, explain the working principle of hydraulic lift. Write an expression for its mechanical advantage. 3 What is meant by the term entropy of a system ? Write mathematical expression for it in a reversible process. Discuss its physical significance. 3

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A cubical thermacole box, full of ice, has side 30 cm and thickness 50 cm. If the outside temperature is 45°C, find the amount of ice melted in 6 hours . (Thermal conductivity (k) for thermacole is 0.01 Js-1m-1°C-1 and latent heat of fusion of ice is 335 Jg-1). 3 An alternating e.m.f. by П/2 or 90°. Define the inductive reactance and write its unit. Draw a...