VISHALINTERNATIONALSCHOOL

Term – II (2017-2018)

Subject: Physics

Time: 3 hrs. Class: XI M.M.: 70

Note: - 1. It is compulsory to attempt all questions.

2. Marks are given against each questions.

3. Handwriting should be neat and clean.

Section-(A)

Q1: Can displacement be greater than distance travelled by an object?1

Q2: What does the slope of velocity time graph represent? 1

Q3: What is Work done in holding a 15kg suitcase while waiting for a bus for 15 minutes? 1

Q4: How will the time period of a simple pendulum change when its length is doubled? 1

Q5: What is the range of audible sound?1

Q6: Write copper,steel. Glass and rubber in the order of increasing coefficient of elasticity? 1

Q7: Why is gravitational potential energy Negative?1

Section-(B)

Q8: The position of a particle is given by 0 k where t is in second and the coefficients have the proper units for to be in meters.Find the velocity and acceleration of the particle in magnitude and direction at time =3.0 s 2

Q9: What is the cause of sliding Friction?2

OR

Q10: Aconstant retarding force of 50N is applied to a body of mass 20kg moving initially with a speed of 15m/s. How long does the body take to stop? 2

Q11: Explain the term: -2

i) Stress

ii) Strain

Or

Q12: State and Prove hooker’s low.2

Q13: Write a short note on hydraulic lift.2

Q14: State second law of thermodynamics.2

Section-(C)

Q15: The periodic time of body executing S.H.M is 2 seconds. After how much interval from t=0, will its displacement be half of its amplitude? 3

Q16: Distinguish between sound waves and radio waves of same frequency says 15 KHZ. 2

Q17: What is simple pendulum? Find an expression for the time period and frequency of a simple pendulum. 3

Q18: A Refrigerator is to maintain eatable’s kept inside at 90C, if room Temperature is 360C Calculate the coefficient of performance. 3

Q19: State and prove Pascal law.3

Q20: A Saturn year is 29.5 times the earth year .How far is the Saturn from the sum if the earth is 1.5108 km away from the sun? 3

Q21: A heater gives heat at rate of 100W. It is used to heat 50gm water from 200C to 300C. Find the time taken to do so [Cw = 4.25/g0C]. 3

Q22: 10gm water at 800C is mixed with 50gm Cu at 10 0C .Find the temp.of mixture.

[Cw= 4.25/g0C, Cu =0.45/g0C]4

Q23: Define trajectory of a projectile and hence derive equation of motion of the projectile when projected at an angle Q with horizontal direction. 4

Section-(D)

Q24: State and Establish principle of conservation of energy.5

Q25: Explain kepler’s low of planetry motion and deduce Newton’s law of gravitation from them. 5

Q26: State and Prove Bernoulli’sTheorem.5

Q27: Derive an Expression for work done in adiabatic process.5

Q28: Explain: -5

i) Boyle’s law

ii) Charle’s Law why they are not applicable to real gases at all states?

Or

Q29: Find an expression for the pressure exerted by a gas and establish its relation with kinetic energy of the gas. 5