SUBJECT: PHYSICS WORKSHEET 2018-19 CLASS: X 1. Define the principal focus of concave mirror. 2. We wish to obtain an erect image of an object using concave mirror of focal length 15 cm. What should be the range of distance of the object from the mirror? Draw the ray diagram. 3. Name the types of mirror used in the following:- a. Rear view mirror of vehicles b. Solar furnaces Support your answer with reason. 4. An object is placed between infinity and pole of convex mirror. Draw a ray diagram and also state the position, size and nature of the image formed. 5. Define 1 dioptre of power of a lens. 6. The refractive index of water is 1.33 and speed of light in air is 3X10 m/sec. Calculate the speed of light in water. 7. Draw a ray diagram to represent the nature and size of the image formed by a convex lens for the object placed at 2F 1. 8. A concave lens has focal length of 20 cm. At what distance from the lens a 5 cm tall object be placed so that it forms an image at 15 cm from the lens? Also calculate the size of the image formed. 9. Define; a. Current b. Potential difference c. Electric power d. Electric Resistance 10. (a) State Ohmʼs Law (b) State Jouleʼs law of heating 11. Define: a. One Ampere b. One Volt c. One Watt d. One Ohm e. One KWh 12. On what factors do the resistance of the conductor depends? Write the SI unit of resistivity. 13. (a) Why is the tungsten used almost exclusively for filament of electric lamps? (b) Why is series arrangement not used for domestic circuits? 1 P age WORKSHEET X STD PHYSICS 2018-19
14. Derive an equation for an equivalent resistance when resistors are connected in series and in parallel. 15. List the properties of magnetic lines of force. 16. State; (a) Flemingʼs left hand rule (b) Right hand thumb rule (c) Flemingʼs right hand rule. 17. The magnetic field in a given regions is uniform. Draw a diagram to represent it. 18. Explain the principle of electric motor. Write its uses. 19. Draw labeled diagram of an electric motor. 20. Why does the cord of an electric heater not glow while the heating element does? 21. Draw a ray diagram to obtain erect and diminished image of an object using a mirror. 22. Write the uses of concave mirrors. 23. Explain the principle of electric generator. Draw labeled diagram. 24. What is a fuse? Write its function. 25. What is earthing and short circuiting? 26. Explain the two methods to induce current with the help of an activity. 27. What is an electromagnetic induction? Name the device used to detect the presence of current in the circuit. 28. Write the frequency of alternating current (AC) in India. How many times per second it changes its direction? 29. What is an electromagnet? Draw a circuit diagram to show how a soft iron can be changed into an electromagnet by a solenoid. Identify the region in the solenoid where field is uniform. 30. The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should the position of the object be relative to the mirror? Draw a ray diagram to justify your answer. 31. A copper wire has a diameter 0.5mm and resistivity of 1.6 X 10 Ohm meter. What will be the length of this wire to make its resistance 10 Ohms? How much does the resistance changes if the diameter is doubled? 32. Two conductors A & B of resistance 5 Ohms and 10 Ohms respectively are first joined in parallel and then in series. In each case the voltage applied is 20V. a. Draw the circuit diagram to show the combination of these conductors in each case. b. In which combination will the voltage across the conductors A & B be the same? c. In which arrangement will the current through A & B is the same? 2 P age WORKSHEET X STD PHYSICS 2018-19
d. Calculate the equivalent resistance for each arrangement. 33. (a) Write three measures to be taken to avoid overloading of domestic circuits. (b) Name and state the rule to determine the direction of the; I. Magnetic field produced around a straight conductor carrying current, II. Current induced in a coil due to its rotation in a magnet field. 34. (a) Why do we use rheostat in the circuit? (b) An Ammeter has 20 divisions between mark 0 and mark 2 on its scale. Find the least count of the ammeter. 35. The potential difference across the terminal of a cell is 1.5 Volt, it is connected with a resistance is 30 Ohms. Calculate the current following through the circuit. 36. Draw a labeled diagram to explain the formation of a rainbow in the sky. 37. Why does the clear sky appear blue? How would the sky appear in the absence of the earthʼs atmosphere? 38. A student wants to project the image of a candle flame on a screen 60cm in front of a mirror by keeping the flame at a distance of 15cm from its pole. a. Write the type of mirror he should use. b. Find the linear magnification of the image produced. c. What is the distance between the object and its image? d. Draw a ray diagram to show the image formation in this case. 39. (a) Draw a ray diagram to show the formation of image of an object placed between infinity and the optical centre of a concave lens. (b) Two thin lenses of power +3.5D and -2.5D are placed in contact. Find the power and focal length of the lens combination. 40. (a) Name the defect of vision in which the eye loses its power of accommodation due to old age. (b) With the help of a ray diagram, show the formation of image by i. a hypermetropic eye. ii. correction of hypermetropia by using an appropriate lens. (c) The near point of a person suffering from hypermetropia is at 50cm from his eye. What is the power of the lens needed to correct this defect? 41. a) An object is placed at a distance of 60cm from a convex mirror where the magnification is 1/2. Where the object should be placed to get the magnification of 1/3? b) A small electric lamp is placed at the focus of a convex lens.draw a ray diagram to show this. 42. (i) Define refractive index of the medium. (ii) Light passes through a rectangular glass slab and through a triangular glass prism. Using proper ray diagram, explain in what way does the direction of the two emergent beams differ with respect to the incident beam of light. (iii) Why convex mirror is used as rear view mirror in vehicles? 3 P age WORKSHEET X STD PHYSICS 2018-19
43. Define the power of the lens. What is the power of a convex lens of focal length 25 cm? 44. Name the electric device that converts mechanical energy into electrical energy. Draw the labeled diagram and explain the principle involved in this device. 45. What is the function of an earth wire? Why is it necessary to earth metallic appliances? 46. Define electric resistance of a conductor. 47. Write the SI unit of electrical resistivity. 48. A student has focused the image of a candle flame on a white screen using a concave mirror. The situation is as given below; Length of the flame = 1.5 cms. Focal length of the mirror = 12 cms. Distance of flame from the mirror = 18 cms. If the flame is perpendicular to the principal axis of the mirror, then calculate the following; (a) Distance of the image from the mirror (b) Length of the image (c) Draw the ray diagram 49. Name and state the rule to determine the direction of force on a current carrying conductor when placed in a magnetic field. 50. Explain how can a permanent magnet be made with the help of a solenoid? 51. What is myopia? List two causes for the development of this defect. How can this defect be corrected using a lens? Draw ray diagram to show the image formation in case of (i) defective eye and (ii) corrected eye. 52. A student obtained a sharp image of a lighted candle on a screen using a concave lens. Now he wants to focus a distant lamp on a far away electric pole. In which direction should the lens be move for this purpose with respect to the screen, to get a sharp image on the screen? Justify your answer. 53. In a given ammeter, a student sees that needle indicates 17 divisions in ammeter while performing an experiment to verify Ohmʼs law. If ammeter has 10 divisions between ) and 0.5A, then what is the value corresponding to 17 division. 54. An electric iron has a rating of 750W, 220V.calculate the, a. current flowing through it, and b. its resistance when in use. 55. List the properties of magnetic field lines. 56. Describe an activity to demonstrate the pattern of magnetic field lines around a straight conductor carrying current. 4 P age WORKSHEET X STD PHYSICS 2018-19
57. Consider the following circuit diagram. If R 1 =R 2 =R 3 =R 4 =R 5 =3Ω, find the equivalent resistance Rs of the circuit. 58. The refractive index of diamond is 2.42. What is the meaning of this statement? 59. (i) What is the function of earth wire in electrical instrument? (ii) Explain what is short circuiting of an electric supply. 60. The heating elements of electric toaster and electric iron are made up of an alloy rather than a pure metal. Why? 61. What is lateral displacement of light? List any two factors on which the lateral displacement in a particular substance depends? 62. An object 2cm in size is placed at 30cm in front of a concave mirror of focal length 15cm. At what distance from the mirror should a screen be placed in order to obtain a sharp image.find the nature and the size of the image formed. 63. With the help of a ray diagram Explain why a convex mirror is preferred as rear view in vehicles. 64. A Given wire is stretched to double its length. How will its resistance change? 65. What is a good source of energy? 66. Why do star appear to twinkle? Explain. 67. Draw a ray diagram to show the formation of images by a concave mirror when the object is placed- (a) between its pole and focus (b) between centre of curvature and focus. 68. The image of an object formed by a lens is real, inverted and of same size as the object. If the image is at a distance of 40 cm from the lens, what is the nature and the power of the lens? Draw ray diagram to justify your answer. 69. Name the three common defect of vision.what are their causes? Name the type of lens used to correct each of them. Note: Learn all the exercises questions from the text book. Prepared by: Mrs. Shaheeda Khanum IX X Boys Section 5 P age WORKSHEET X STD PHYSICS 2018-19