SECTION – A
Note: a) All questions are of very short answer type.
b) Answer all questions.
c) Each question carries 2 marks. 10 $ 2 = 20
1. “Equations v = u+at and v2 = u2+2as can be derived by method of dimensional analysis”. Is this statement correct or not? why?
2. What is coefficient of restitution? Mention its values under different conditions.
3. A particle of mass 2Kg moves with velocity 2 i Λ +3 Λ jms-1, and
another particle of mass 3Kg moves with velocity 4 Λ i-6 Λ jms-1.
Find the velocity of centre of mass of this system.
4. What is angle of friction? What is the relation between the angle of friction and the coefficient of friction?
5. What is radius of gyration? On what factors it depends?
6. What is schwarzchild radius? Write an expression for it and mention the factors in the equation.
7. A drop of mercury at 20°C has radius 3mm. Surface tension of mercury at that temperature is 4.65×10-1Nm-1. What is the excess pressure inside the mercury drop?
8. Can you find any substance that contracts upon heating? Give an example.
9. Certain mass of ice is converting into water form. Is this process Isothermal? or Adiabatic? Why?
10. Top of the ceilings of houses are generally painted white in summer. Why?
SECTION – B
Note: a) All questions are of short answer type.
b) Answer any six questions.
c) Each question carries 4 Marks. 6 $ 4 = 24
11. Write the law of parallelogram law of forces. Derive expressions
for the magnitude of the resultant and the direction.
12. Show that the path of a projectile is a parabola.
13. Explain why it is easier to pull the lawn roller than to push it.
14. Write the principle of conservation of angular momentum and mention two applications.
15. Derive an expression for the variation of ‘g’ with altitude (h).
”It is erroneous to conclude that at h = R/2, g = 0; R is the radius of the earth”. Explain why this statement is correct?
16. Describe the behaviour of a wire under gradually increasing load.
17. State Bernoulli’s theorem and using the equation of the theorem
explain why a man standing nearly a fast moving train feels as if the train is pulling him toward it.
18. 5 moles of hydrogen when heated through 20K expands by an amount of 8.3 ×10-3m3 under a constant pressure of 105 N/m2. If Cv = 20J/mole.K find Cp.
SECTION – C
Note: a) All questions are of long answer type.
b) Answer any two questions.
c) Each question carries 8 marks. 2 $ 8 = 16
19. State the law of conservation of energy and prove it in the case of a body projected vertically upwards. If the power of a water motor is 3kw find how much water it can lift into a tank placed at a height 10m in 1 minute.
20. Define simple harmonic motion. Show that the motion of a simple pendulum is simple harmonic; hence derive an expression for time period of the simple pendulum. An object executing SHM has an acceleration of 0.2ms-2 at a distance of 0.05m from the mean position. Calculate the period of SHM.
21. Describe the specific gravity bottle method along with theory, to determine the coefficient of apparent expansion of a liquid.
The mass of an empty specific gravity bottle is 20g. When it is filled with a liquid at 30°C, the mass of the bottle is 60g. When it is heated to 80°C, 2.2g of liquid is expelled. Find the apparent expansion of the liquid.
Please can you post 2018 model paper
For junior inter