HSEB – Grade XI, Physics, New Course, Question Paper 2012 (2069) – HSEB NOTES, Question Collection Series  Group ‘A’

1. Answer in brief any six questions. 6x2=12 a. How does the kinetic energy of a body change if its momentum is halved? b. If the sun some how collapsed to form a black-hole, what effect would this event have

on the orbit of the earth? c. Can the direction of the velocity of a body be changed when its acceleration is constant? d. If and are non-zero vectors, is it possible for & · both to be zero?

Explain. e. In hot air ballooning, a large balloon is filled with air heated by a gas burner at the

bottom. Why must the air be heated? f. A man drops his briefcase in an elevator but it doesn’t fall to the floor. What can be

concluded about the situation? g. An ice cube floats in a glass of water. When the ice melts, will the water level in the

glass rise, fall or remain unchanged? Explain. 2. Answer in brief any two questions. 2x2=4 a. Frozen water pipe often burst, will a o ak if mercury therm meter bre the temperature of

the thermometer is brought below the freezing point of mercury? If you add heat to an object, do you necessarily increase its teb. mperature? Justify your answer.

c. Why the Polar Regions much cooler than the equatorial regions despite the fact that the Polar Regions are periodically tilted towards sun?

3. Answer in brief any one question. 1x2=2 a. Can a convex mirror ever form real image? Justify your answer. b. A large object when taken away from your eye appears smaller. Why? 4. Answer in brief any one question. 1x2=2 a. Why is it dangerous to take shel er u ing? t nder a tall tree during lightinb. Can two electric lines of force ever intersect each other? Explain.

Group ‘B’ 5. Answer any three questions. 3x4=12 a. State the parallelogram law of vector addition. Derive the expressions for the magnitude

and direction of the resultant of two vectors inclined at an angle from each other. What is geo stationary satellite? Obtain an expression for the al energy of a sab. tot tellite orbiting round the earth. State the principle of consc. ervation of linear momentum. How does the Newton’s third law of motion lead to the principle of conservation linear momentum? Derive an expression for the energy stored in a stretched rod. Define d. the term energy density of a body under strain. Answer any two questions. 6. 2x4=8

a. Define linear and cubical xp Derive an θ

e ansivities of solids. expression for the variation in density of a solid when its temperature is raised from to . Define adiabatic process in thermodynamics. Show that: PVb. r=Constant. Where symbols have their usual meanings. Describe the working of pec. trol engine with the help of P-V diagram.

7. Answer any one question. 1x4=4

a. What is long sightedness? D uss the sightednisc possible causes of long ess. Explain how this defect can be remedied.

b. Derive an expression for lens maker’s formula. 8. Answer any one question.

his th orem to f nd t 1x4=4

a. State Gauss Theorem. Use t e i le d intenshe e ctric fiel ity due to a plane charged conductor.

b. How can a number of capacitors be connected to increase and decrease the effective capacitance? Find the respective expressions for the effective capacitance in each case.

Group ‘C’ Solve any three questions. 3x4=12 9.

a. A man wishes to swim across a river 600m wide. If he can swim at the

rate of 4km/h in still water and the river flows at 2km/h. then in what direction must he swim to reach a point exactly opposite to the starting point and when will he reach it? A ballet dancer spins with 2.4rev/sec with her arms outstretched when the moment of b. inertia about the axis of rotation is I. With her arms folded, the moment of inertia about the same axis becomes 0.6I. Calculate the new rate of spin. A cricket ball of mass 145gm is moving with a velocity of 14m/s and is being hit by a c. bat, so that the ball is turned back with a velocity of 22m/s. The force of blow acts on the ball for 0.015 sec. Find the average force exerted by the bat on the ball. Castor oil at 20 has a coefficient of viscosity 2.42 Ns/m2 and density 940kg/m3.

mid.

Calculate the ter nal velocity of a steel ball of radius 2mm falling under gravity in the oil. Solve any two questions. 2x4=8 10.

a. Air at a temperature of and es N/m2 p2.7x1025 molecules per cub cubic m

273K a pr sure of 1.01x105 ressure contains ic meter. How many molecules per eter will be there

at a place where the temperature is 223K and the pressure is 1.33x10-4 N/m2? 10 gm of steam at 100 is passed into a mixture of 100gm of water and 10gm of ice at 0 . Find the resulting temperature of the mixture.

b.

c. A glass vessel of volume 50cm3 is filled with mercury and is heated from 20 to 60 . What volume of mercury will overflow?

11. An object to the left of a lens is imaged by the lens on a screen 30cm to th r e lens. When the lens is moved 4cm to the

e ight of thright, the screen must be moved 4cm to the left

to refocus the image. Determine the focal length of the lens. 4 Two charges +1x10-6C and -4x10-6 are separated by a distance of 2m. Determine the position of the null point. 3

12.

- O -