CBSE Class - XI Physics (Set 1) Last year Paper (2015-16)

Time: 3 Hrs. M.M: 70

General Instructions:

1. Question 1 to 5 one mark.
2. Question 6 to 10 each two mark.
3. Question 11 to 22 each three mark.
4. Question 23 is value based question and carry four marks.
5. Questions 24 to 26 each five mark.

Section A

1. Write the dimensional formula of impulse and name of the physical quantity having same dimension.

Write the relation between two angles for which horizontal ranges will be equal.

1. On what factors does the two vectors a and b to be perpendicular to each other.
2. Write the condition for conservation of mechanical energy of a system.
3. What is the ratio of escape speed of the earth and escape speed of the moon?

Section B

6. Define wavelength. Why there is no transfer of energy by standing waves?

1. Is the heat supplied to a system always equal to the increase in its internal energy?
2. Resultant of two vectors of equal amplitude is equal in magnitude with one of the vectors, calculate the angle between them

or

A woman throws an object of mass 500 g with a speed of 25 m/s.

1. What is the impulse imparted to the object?
2. If the object hits a wall and rebounds with half the original speed, what is the change in momentum of the object?

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1. If length of a pendulum is increased by x%. Find error in time per day.
2. Define coefficient of linear expansion and coefficient of volume expansion of solid. How are they related?

Section C

1. The density of a linear rod of length L varies as <math>\rho = \alpha + \beta x</math>, where x is the distance from the left end. Locate the centre of mass.
2. Two particles each of mass m go round a circle of radius a under the action of their mutual gravitational attraction. Find the speed of each particle. Also analyse in terms of kinetic energy and gravitational potential energy.
3. Find the angle made by a cyclist with the vertical while taking a circular turn of radius a. Also state the forces which are providing centripetal acceleration and maintain vertical equilibrium.
4. What is the moment of inertia of a solid sphere of radius R about one of its diameter. If moment of inertia about the parallel tangent is <math>I_{\rm 0}</math> . Also, state the theorem of perpendicular axes.
5. Find the expression for potential energy of a strained body.
6. State Torricelli's law for efflux speed of a liquid and prove it. Find the efflux speed if height is 5 m.
7. Establish ideal gas equation in terms of gas constant R, volume V, pressure p, temperature T and number of moles n.

<math>\mathbf{or}</math>

For an oscillating pendulum, find the time period of oscillation.

1. Two separate air bubbles formed of the same liquid (surface tension T) come together to

form a double bubble. Find the radius and the sense of curvature of the internal film surface common to both the bubbles.

19. The position of a particle is given by <math>{\rm r}=\left(3t\hat{i}-2t^2\,\hat{j}+4\hat{k}\right)m</math> where, t is in second and the coefficients have the proper units for r to be in metres.

1. Find the v and a of the particle?
2. What is the magnitude and direction of velocity of the particle at t = 2 s?
3. A10 kW drilling machine is used to drill a bore in a small aluminium block of mass 8 kg.

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