**Short Questions**

1. Are radians and steradians the basic units of SI?

2. Define error. Also describe possible causes of error.

“3. Define following?

Base Units (ii) Derived Units (iii) Supplementary Units”

4. Define Physics? Describe its main areas of research.

5. Define random and systematic error?

6. Define significant figures?

“7. Define the following branches of modern physics

Nuclear Physics (ii) Particle Physics (iii) Relativistic Mechanics (iv) Solid State Physics “

8. Define the radians and steradian?

9. Differentiate among precision and accuracy.

10. Differentiate among the base and derived quantities.

11. Differentiate among the physical and biological sciences.

12. Differentiate among the random and systematic error.

13. Distinguish between base units and derived units?

14. Distinguish between Biological sciences and Physical sciences?

15. Does a dimensional analysis given any information on constant of proportionality that may appear in an algebraic expression?

16. Give the drawbacks to use the period of a pendulum as time standard?

17. How are random error and systematic error reduced?

18. How is degree of random error estimated?

19. How is the uncertainty in the time period of a vibrating body found?

20. How many significant figures are there in following measurements?

21. How the base quantities are measured?

22. How will you differentiate error from uncertainties?

23. Is it possible to have two quantities with the same dimensions but different found?Give for examples?

24. Name several repetitive phenomena occurring in nature which could serve as reasonable time standards?

25. Name the supplementary units?

26. State the principle of homogeneity of dimensions?

27. The period of simple pendulum is measured by a stop watch.What type of errors are possible in the time period?

28. Under what conditions zeros are not significant?

29. Under what conditions zeros are significant?

30. What are SI units of plane angle and solid angle?

31. What are significant figures?

32. What are the advantages of dimension analysis?

33. What are the characteristics of an ideal standard?

34. What are the significant figures? Describe their significance.

35. What are two types of errors?

36. What do you know about international system o

37. What do you know about physical quantities? Also describe their significance.

38. What do you know about the dimension analysis?

39. What do you know about the natural philosophy?

40. What do you mean by dimensions of physical quantity?

41. What do you mean by prefixes?

42. What do you mean by scientific notation? Describe the following numbers in scientific notation.

43. What do you mean by system international?When was it established?

44. What do you understand by a unit?

45. What does the word micro signify in the words micro wave oven?

46. What is homogeneity principle?

47. What is Rounding off data process?

48. What is scientific notation?

49. What is the importance of standard units in physical science?

50. What types of errors are possible in measuring the time period of pendulum by stop watch?

51. What types of natural phenomenon could serve as alternative time standards?

52. When is the equation said to be dimensionally correct?

53. Which areas in the study of Physics involve describe briefly?

“54. Which of the following measurement is more precise and which of them is mare accurate.

Length of object is recorded as 25.5 cm using meter rod.

The length of object is measured as 0.45cm using vernier calipers. “

55. Why do we find it useful to have two units for the amount of substance the kilogram and the mole?

56. Write down any two drawbacks of dimension analysis?

57. Write down the dimensions of velocity, acceleration and force?

58. Write down the significance of science and technology. Also describe the role of physics in the development of science and technology?

59. Write down the two points which should be kept in mind while using units?

**Long Questions**

1. Describe the principle of Homogeneity of Dimensional Analysis?

2. How will you assess the total uncertainty in the final result? Explain it fully in different cases.

3. Define and explain Random Error and Systematic Error in the measurement of a physical quantity.

4. Show that the expression vf = vi + at is dimensionally correct, where vi is the velocity at t=0 and vf is the velocity at time t.

5. Define meter and kilogram.

6. What is meant by scientific notation? Explain.

7. How do you access the total uncertainty in the final result for multiplication and division? Explain with example.

8. Write down uses of dimension analysis

9. A light year is the distance light travels in one year. How many metres are there in one light year: (speed of light = 3.0 x 10⁸ ms⁻¹).

“10. a) How many seconds are there in 1 year?

b) How many nanoseconds in 1 year?

c) How many years in 1 second?”

11. The length and width of a rectangular plate are measured to be 15.3 cm and 12.80 cm, respectively. Find the area of the plate.

12. Add the following masses given in kg upto appropriate precision. 2.189, 0.089, 11.8 and 5.32.

13. Find the value of ‘g’ and its uncertainty using T = 2π √lglg from the following measurements made during an experiment. Length of simple pendulum l = 100 cm. Time for 20 vibrations = 40.2 s. Length was measured by a metre scale of accuracy upto 1 mm and time by stop watch of accuracy upto 0.1 s.

14. 1.6: What are the dimensions and units of gravitational constant G in the formula F=Gm₁m₂/r²

15. Show that the expression of vf =vi +at is dimensionally correct, where vi is the velocity at t =0 , a is acceleration and vf is the velocity at time t.

16. The speed v of sound waves through a medium may be assumed to depend on (a) the density ρ of the medium and (b) its modulus of elasticity E which is the ratio of stress to strain. Deduce by the method of dimensions, the formula for the speed of sound.

17. Show that the famous “Einstein equation” E = mc² is dimensionally consistent.

18. Suppose, we are told that the acceleration of a particle moving in a circle of radius r with uniform speed v is proportional to some power of r, say rⁿ, and some power of v, say vᵐ , determine the powers of r and v ?