1.         A body is moving with uniform acceleration. Can the direction of its velocity change?

2.         A body is thrown vertically upward. What is the magnitude of its acceleration?

3.         What is the condition in which a body moving with uniform speed has variable velocity?

4.         Under what condition a body whose velocity is directed towards east has acceleration directed west.

5.         According to first law of motion every object continues its state of rest or motion but the boy riding the push bike stops after some time if he stops the pedaling. Why?

6.         How do we move forward?

7.         Explain why it is dangerous to jumps from a fast moving train?

8.         Why do we fell a jerk when we fire a gun?

9.         When a person is sitting on the chair why does no he fall on the ground?

10.     The Earth pulls the moon. Why does it no fall?

11.     What is the cause of friction?

12.     Why is the rolling friction less than the sliding friction?

13.     Why a book lying on a table is in rest?

14.     How does a paratrooper descend with a uniform velocity. When the Earth pulls them?

15.     Why does merry-go-around not move until some force is applied to create torque?

16.     If one side of a book lying on a table is raised a little by application of force, the book will return to its original position, when the force is withdrawn. Why?

17.     What is the direction of the motion of a body describing a unifrom circular motion?

18.     A body is moving in a circle with uniform speed. Is its velocity also uniform?

19.     Is there any acceleration in a body moving in a circle with a uniform speed. What do we call that acceleration?

20.     What is the function of the acceleration acting on a body moving in a circle? What is the direction of the acceleration?

21.     To move a car along a round track a centripetal force is necessary. How is the force provided?

22.     Why is the value of g at a hill less than its value at the sea shore and is less at the poles than at the equator?

23.     What will the value of g at a distance equal to the radius of the earth and at a distance twice the radius of earth?

24.     Why we use negative sign in the value of retardation or deceleration/

25.     Why does a body or ball thrown upward always fall on the ground?

26.     Why does a screw jack always have efficiency less than 100%?

27.     Why does a body loose more weight in honey than in water?

28.     Why is the steel more elastic than rubber?

29.     Police make check post with sand bags or concrete block why?

30.     Why it is easy to stop the bicyccle than a car when their velocities are same?

31.     What type of work is done by a fixed pulley and movable pulley?

32.     In what ways are lever, an inclined plane and a pulley alike?

33.     Why does an object float?

34.     Why does a piece of stone sink in water but a ship with a huge weight floats?

35.     A person does some work on the computer but physicist say that he did not do any work why?

36.     Why do some solids such a wood, cloth and plastic foam have poor conductivity?

37.     Small gaps are left between the ends of two adjacent rails. Why is it so?

38.     When a flask having narrow neck full of water is heated water surface in the neck falls in the beginning. Give reasons?

39.     Why are the rocks broken during winter season?

40.     Why do the water supply pipes bursts during winter?

41.     How do fish and other aquatic animals in oceans and seas survive in extremely cold water?

42.     Why is steam at 100°C more injurious than boiling water?

43.     Why a thermometer does not show any change in temperature when the heat is given to ice at 0°C?

44.     Why does food cooked in pressure cooker take shorter time?

45.     Why is tea made on a mountain not tasty and the meat and pulse take longer time to cook?

46.     Both in evaporation and boiling molecules with higher than average kinetic energies leave the system. Why the evaporation cools the system but boiling does not?

47.     Evaporation is cooling process?

48.     Boiling point of a liquid remains constant although heat is continuously supplied to the liquid?

49.     How does gas exert pressure?

50.     What will be effect of temperature on the pressure of a gas?

51.     Why does the density of a body decreases on heating?

52.     What is the effect of pressure on melting point or freezing point?

53.     What is the effect of increase of pressure on the boiling points of liquids?

54.     What is the effect of the lowering of pressure on the boiling point of water?

55.     Why do fishes die in newly boiled water, which has been cooled?

56.     Why does water spilled on a floor evaporates more rapidly than the same amount of water in a glass?

57.     Would a pressure cooker be of any value on the Mount Everest?

58.     Why cannot liquids and solids be compressed as gases can?

59.     Why is the inner portion of railway track kept lower than the outer portions on turns?

60.     Why at 4°C the density of water is maximum?

61.     Why has the coastal area moderate climate?

62.     How is the wavelength of stationary waves related to node and antinode?

63.     While crossing a bridge the soldiers are order to break the steps. Why?

64.     How do we identify the voices of our friends?

65.     Why is the flash of lightening seen earlier than the sound of thunder?

66.     Why are the explosive sounds produced in the sun not heard on the earth?

67.     Why does a part of car begin to vibrate very violently at a certain speed?

68.     If we walk fast why are tired quickly?

69.     Why we cant hear echo in our room?

70.     The pendulum wall clock gives wrong time in summer why?

71.     Why do we use light colored clothes in summer?

72.     Why do we use dark clothes in winter?

73.     Why doe we get sufficient light of sun in our rooms not directly open to sun?

74.     Why does sunlight reach us before sunrise?

75.     How is rainbow formed?

76.     Index or refraction of every substance is greater than 1?

77.     A watchmaker uses convex lens while repairing watches, why?

78.     If the burning end of a stick is moved in a circle at night, a circle of light is seen, why?

79.     Why do the old people use the bi-focal lenses?

80.     Why is light dual in nature?

81.     Why does atom emit radiation or light?

82.     Why is the atom electrically a neutral particle?

83.     Why do insulators or non-conductors not allow the flow of charge?

84.     Why do conductors allow the flow of charges?

85.     Why do we use the term conventional current?

86.     Why is the electric current in a material that conducts electricity zero in the absence of an applied electric field, when the free electrons are always on move?

87.     When does a current carry conduction and placed in a magnetic field experiences a force?

88.     How is the desired line of telephone dialed contacted?

89.     Why does the compass needle deflect when  magnet is brought near it?

90.     Why does freely suspended magnet points in north south direction?

91.     Why does a ray of light change its direction when it enters a different medium obliquely?

92.     Why do the stars twinkle/

93.     Why do oil spots on a road become coloured when it rains?

94.     Why are danger signals in red colour when the eye is more sensitive to yellow and green?

95.     Why electrician wear rubber shoes during repairing electric fault?

96.     Why do skiers ski on ice easily?

97.     An ice ball is made by pressing the pounded ice?

98.     Why does a traveler travelling in a desert on a hot sunny day observe at a distance the presence of water?

99.     The front of the fast moving car or aeroplane is made oblong why?

100. Why is the colour of sky blue?

101. The clinical thermometer has  narrow bend in its capillary bore near the mercury bulb, why?

102. Why is the germanium or silicon an insulator at low temperature when pure?

103. How does a hole flow?

104. Why is a radar useful in fog, smoke mist and clouds?