PRACTICE PAPER - 4 CLASS : X SUBJECT: SCIENCE (only PHYSICS question shown here) (Based on Full Syllabus) M.M.: 80 DURATION: 3 HRS |
GENERAL INSTRUCTIONS: (i) All questions are compulsory. (ii) The question paper has five sections and 12 questions. All questions are compulsory. (iii) Section–A has 4 MCQs and 2 assertion-reason type of 1 mark each; Section–B has 1 questions of 2 marks each; and Section–C has 3 questions of 3 marks each; Section–D has 1 questions of 5 marks each; Section–E has 1 case based question of 4 marks. (iv) Internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions. (v) For case study questions in section E, there is one choice in one subpart, with 3 questions based per case study. |
SECTION A (MCQs)
| Q1 | The different colours split in prism because, (a) The follow different paths (b) The prism offers different refractive index to different colour (c) Of the shape of the prism (d) of the Tyndall effect |
Q2 | In what respect, solenoid is similar to a bar magnet ? (a) the magnetic field of solenoid is similar to that of bar magnet (b) Same current flows in both (c) poles can be interchanged in both solenoid and bar magnet (d) The strength of magnetic field cannot be changed in both
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| Q3 | A person went for a medical check-up and found that the curvature of his eye lens was increasing. Which defect is he likely to suffer from? (a) Myopia (b) Cataract (c) Presbyopia (d) Hypermetropia |
| Q4 | No current flows between two charged bodies when connected, if they have same: (a) Capacity (b) charge (c) potential (d) temperature |
Q5 to Q6 are assertion-reasoning based questions. These consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate options given below: (a) Both A and R are true and R is the correct explanation of A. (b) Both A and R are true but R is not the correct explanation of A. (c) A is true but R is false. (d) A is false but R is true. |
| Q5 | Assertion : The light of violet colour deviates the most and the light of red colour the least while passing through a prism. Reason : For a prism material, refractive index is highest for the violet colour and lowest for the red colour |
| Q6 | Assertion(A) : Longer wires have greater resistance and smaller wires have lesser resistance. Reason(R) : Resistance is inversely proportional to the length of the wire. |
SECTION B
Q7 to Q7 are very short answer questions
Q7 | When we place a glass prism in the path of a narrow beam of white light, a spectrum is obtained. What happens when a second identical prism is placed in an inverted position with respect to the first prism ? Draw a labelled diagram to illustrate it. OR Give reasons for each of the following: (a) the sky appears dark instead of blue to an astronaut in space. (b) Red light is used as the stopping light at traffic signals. |
SECTION C
Q8 to Q10 are short answer questions
Q8 | Analyse the following observation table showing variation of image-distance (v) with the object distance (u) in case of a convex lens and answer the questions that follows:
(a) What is the focal length of the convex lens ? Give reason to justify your answer. (b) Find the missing value X at S.No. 6. |
Q9 | (a) State Snell’s Law. (b) Find the absolute refractive index of a medium in which light travels with a speed \( 2.25\times 10^{8} \;ms^{-1}\). Given the speed of light in vacuum is \( 3\times 10^{8} \;ms^{-1}\). (c) Draw a labelled ray diagram to show the path of a ray of light travelling from diamond to water. The refractive indices of diamond and water are 2.42 and 1.33 respectively. |
Q10 | A person is unable to see distinctly the words printed on a newspaper. (a) Name the defect of vision the person is suffering from? (b) List two possible causes of this defect. (c) Draw a ray diagram to show this defect may be corrected using a lens of appropriate focal length. OR Neha’s grandfather was prescribed a bifocal lens for correction of his vision by an eye specialist. (a) Name the eye-defect from which the grandfather is suffering from ? (b) List two causes for the development of this defect. (c) The bifocal lens consists of two different lenses of power – 2.5 D and + 1.5D respectively. Find the focal length of the corrective lens which corrects the near vision. |
SECTION D
Q11 to Q11 are long answer questions
Q11 | (a) What do the following circuit symbols represent?
(b) In the circuit given below (i) Would any bulb glow when plug key K is in an open position? (ii) Determine the reading of the ammeter when key K is closed. (iii) Why is tungsten used almost exclusively for filament of electric lamps? |
SECTION E
Q12 to Q12 are case-based / data-based questions with 2 to 3 short sub-parts.
Internal choice is provided in one of these sub-parts
Q12 |
Figure shown above gives a schematic diagram of one of the common domestic circuits. In our homes, we receive supply of AC (alternating current) electric power through a main supply, either supported through overhead electric poles or by underground cables. One of the wires in this supply, usually with red insulation cover, is called live wire (or positive). Another wire, with black insulation, is called neutral wire (or negative). In our country, the potential difference between the two is 220 V. These wires supply electricity to separate circuits within the house. Often, two separate circuits are used, one of 15 A current rating for appliances with higher power ratings such as geysers, air coolers, etc. The other circuit is of 5 A current rating for bulbs, fans, etc. The earth wire, which has insulation of green colour, is usually connected to a metal plate deep in the earth near the house. This is used as a safety measure, especially for those appliances that have a metallic body, for example, electric press, toaster, table fan, refrigerator, etc. (a) Name two safety measures commonly used in domestic electric circuits. (1) (b) What is a short circuit ? (1) (c) (i) What is alternating Current (AC) ? (1) (ii) Most power stations constructed these days produce AC ? Write one advantage of AC over DC? (1) OR (c) An electric oven of 2 kW power rating is operated in a domestic electric circuit (220 V) that has a current rating of 5 A. What result do you expect? Explain. (2) |
