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DPSINTERNATIONA SCHOOL 36 Aroozoo Avenne (opp Srin Park) Singapore 539842 Tel: (65) 62856.300 Fax: (65) 6285S1670 Website: www.dps.edu.sg FIRST PRELIMINARY EXAMINATION 2023 - 2024 MARKS: 80 GRADE:10 ICSE SUBJECT: PIIYSICS DATE::11:2023 TIME: 2 hrs. INSTRUCTIONS 1. Youare rquired to utilize the first 15 minutes for reading the Question paper. 2. You will notbe allowed to writeduring this time. 3. Neaness should be maintained by avoiding overwriting or striking oul. 4. Do not use whiteners or correction tapes. 3. Do not copy the question 6. You are advised toanswver only that number of questions as mentioned in the question paper. Section A is compulsory. Altempt any four questions from Section B. The itended marks for questions or parts of questions are given in brackets/ / SECTIONA(40 MARKS) (Attempt all the questions) Question 1. Choose correct answer tothe questions from the given options. (15] i) The K.E of agiven body depends on the a. Position b. Centre of gravity of the body c. Momentum d. Displacement (i ) A given nucleus of an atom consists of 146 neutrons and 95 protons. It decays after emitting an alpha particle. How many protons and neutrons are left in the nucleus after an alpha emission? a. Protons = 93, neutrons = 144 b. Protons =95, neutrons 142 C. Protons 89, neutrons 144 d. Protons 89, neutrons 142 image in terms i ) For aconvex lens, the minimum distance between an objcct and its real of focal length () of a piven lens must be. a. 1.5f b. 2sf ( ) According to the old conviction of colours the colour of the earth wire is b green d. rod () When a ray of light enters from a denser medium to rare a. The light rav towards the nomal b. The speed of bends light increases c The angle of incidence is greater than the d. Its wavelength decreases (vi) The phenomenon of light that a. Refraction b. Reflection medium then angle of refraction governs the functioning of the optical fiber is c. Scattering d. Total internal reflection (vii) Which of the following nuclear a. Alpha b. Beta c. Gamma d. radiations can be stopped by a sheet of paper? None of these (vii) Which of the following liquids is most suitable for radiators in cars? a. Liquids P with specific heat b. Liquid Q with specific heat capacity 4000 Jkg K c. Liquid R with specific heat capacity 2000J kg' K capacity I500 J kg' K! d. Liquid S with specific heat capacity 2100 J kg' K! ix ) When a current Iflow through a wire of resistance R for timetthen the electrical energy produced is given by a. PRT b. IRT c. IRT d. IRT? (v) When a ray of light travels norrmally to the given surface, then the angle of reflection a 180 b 90 d 45 (xi) A main switch in the main distribution board is present in a A live wile b Aneutral wire C A live as iell as Heulual site d. An carth irc (xii) What should be the angle between force and displacement to get the minmum nd maximunwork? a. 90 to 0 b. 0 to 90 c. 45 to 90 d. 0 to450 (xii) Absolute refractive index of a transparent medium is always a. Smaller than b. Greater than I c. Lies between 0 and 1 d Negative (xiv) Which of the following is a non-Ohms conductor? a. Filament of a bulb b. Nichrome c. Copper d. Silver (xv) lA current flows through a conductor. It indicates that elecrons pass in ls across the cross-section of the conductor. a. 1.6x 10 19 b. 1.6 x 10 19 C. 6.25 x 10 !8 d. 1 Question 2 i) (a) Define the term potential energy. (b)State whether the following statement is true or false The deviation produced by a prism is independent of the angle of incidence and is same of all colours of light. (c)Give one example of each, Ohmic and Non-Ohmic conductors 3 screcn Alens X Xcan fom an imagc onthe (a) Name thc lens X form magnified image" (b)Is itpossible for this lens to (i) (2) (i) What are background radiations? (iv) of Vaccumulatot connectedto a12 lamp 1cumentIthrongh a1?V Tungsten tlhe ilament. Calculate theresislane of [2) iegligibleiesislanceis 3.0A (: )(a) 1lhen dues a fote du wok" around thc Larth (b) What is thc work donc by thc Moon whcn it rcvolkcs [2] (vi)(a) Define specific resistance of amaterial. (b)State its S.I. units. (21 (vii )(a) Is it possible for ahydrogen H' nucleus toemit an alpha particle? Give a reason for vour answer. |2*5-10| Question 3 (i) Calculate the thermal capacity of 40g of water. (Sp. Heat capacity of water =4200 J/kg"C) () What is meant by nuclear waste? Suguest one effective process for the safe disposal of nuclear waste. (1) AcoIn at the bottom of a trough containing water to a depth of lbcm appears to be 3.75cm raised above from the bottom Calculate the refractive index of Water. (iv) State energy changes in the following cases while in use: (a) An electric iron (b) Aceiling fan. (v) Draw a ray diagram to illustrate how a ray of light incident obliquely on one face of a rectangular glass slab of uniform thickness emerges. SECTION B(40 MARKS) (Attempt any four questions) Question 4 ()A coconut of 45g mass falls from the top of an 80m high tree. (a) Calculate the potential energy possessed by the coconut when it is at the top of the tree. (b)Without calculation, state the kinetic energy with which it strikes the ground and state the principle involved to arrive at the answer. (ii) In the given circuit diagram, Calculate 4 (4] 292 I} 0.4A 12 2 (a) The external resistance of the circuit. (b) The current I. (c) The current I. the hypotenuse of a right-angled (iii) Aray of light PQis incident normally on ABC as shown in the diagram A PrISm (3] P B (a) Copy the diagram and complete the the path of the ray PQtill it emerges from Prism. deviation of the ray? (b) What is the value of the angle of action of the prism is used. (c)Name the instrument where this Question 5. reason freeze at once in cold countries. Give a not do ponds and lakes in Water (a) i) [4] in support of your answer. calorimetry? (b) What is the principle of this principle is based. which (c) Narme the law on of impurities on the melting point of ice. increase (d) State the effect of (3] in shown are joinedtogether as (iii) The resistors of 6.02,2.02and 4.02 respectively 6.0V. m.f. e. ammeter and to a cell of (ii) Give three usesof infrared radiations. the figure. The resistors are connected to an 6.0V SR =40 2 RS=6.02 Calculate (a) the etlective resistance of the circuit. (b) the current drawn from the cell. Question6 (i) Mention the safety measure while handling radio active material. i)Complete the path of the ray through the glass prism of critical angle 42: till itemerges out of the prism. [3] B] (ii) Show that the sum of kinetic energy and potential energy is always conserved /4] in the case of a freely falling body under the effect of gravity. Question 7 (i)Calculate the mass of ice needed to cool 15g of water contained in a calorimeter of mass 50g at 32 C such that the final temperature is 5 C Sp. Heat capacity of calorimeter= 04Jig'c Sp. Heat capacity of water =4.2J/gC Latent heat capacity of ice = 330J/g ( )(a) Name the electrical appliance shown below : 6 (b)Namethe material of the wire uscd in this device. (c).Nanet 0 important characteristics of this wirc. Define power of a lens. (b). Jens has focal length 25 cm. ( i)(a) [3 Calculatethe power of lens Question 8 i Thcfigure shows acircuit. Whcn thc circuit is switchcd on thc anmctcr rcadig la[4| 0.5A. 6.0 V 352 (a) Calculate the value of the unknown resistor R (b) Calculate the charge passing through the 392 resistors in 120s. (c) Calculate the power dissipated in the 392 resistor. (i) (a) Define heat capacity of a substance, (b) Write the SI unit of heat capacity. and specific heal capacity of a (c) What is the relationship between heat capacity [3] substance? [3| (ii)(a) State the laws of refraction of light. angle of emergence(e) (b) Write a relation between the angle of incidence(i), ray of light passing angle of pri sm (A)and the angle of deviation () for a through an equilateral prism ***}nd of paper 7 %* *
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