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G) NfflM Monjtt EdUCl!lonal T1111r1 JAMNABAI NAA21! SCftOOL f:':l oontactus@jns.ac.ln Narsee Mo1191 Bhavan, Narsee Monjee Marg, N.S.Road No. 7, J.V.P.D. Scheme, Vile Pa~e (W), Mumbai - 400 049, lncla. \_ +91 22 6915 7575 / 6915 7576 - iii\ www.jns.ac.ln SECON D PRELIMIN ARY EXAMIN ATION ..,. January 2023 PHYSICS \ Std.10 Time: 2 hrs, Marks:80 Date: 5.01.2023 Answer to this paper must be written o~ the paper provided separately. You will not be allowed to write during the first 15 minutes. .!g.~jp,tff!,~f:\il; ;'.,. :tt que1l ~}~ftj:\ _;?;/ /.;':-, ,,h{,~_;:~~i This time is to be s~nt in readltjg.J~ i' ,, ... The time given at the head oft!ifs,PdP,.e,r is the time alldw'e11for writing tfii!i'{ffeSWers. ;;}~ ' , , ;; Section A is compulsory. Attempt aiiy.jour questions from Section ~ The intended marks for questions or parts of~ stions are'gi;){,fP.J /1.~'I~ts []. ''\11, y ;{~)~/!$:f SECTION A (AttemjJh(f questions from this Section.) Question 1 Choose the correct answer to the questions from the giv'en options. (i) [15] A bucket full of water is lifted from a w~ll directly using hand in this case: (a) We apply effort iri po)Vnward direction. (b) We apply effort at c'dn:i~nient point on bucket. (c) We apply effort upwarilii<1inst gravity. (d) We apply effort downward\against gravity. [ l] Refractive index of glass is 3/2 with t~pect to air so on viewing it from air, the glass slab appears: (a) only 1/3 of its real thickness . (b) only 2/3 of its real thickness(c) only 1/3 of its apparent thickness (d) only 2/3 of its apparent thickness [I] : v (ii) 1 (iii} A sheet of ice floats on water. The source of sound Sis positioned at the edge of the ice sheet and four microphones are placed at equal distance from S. Which microphone detects the sound from S first? [I] air (a} (b) (c} (d) (iv} A B C D Forth(l same increased fo [I) (a) _, iio " ( t 'f " 13' ' (b}1&1 ~locity becomes f'l:Zh ''(d} (v) /6 An alternating (a) Th its value after each time interval of: wos 1 [I) 1 50 1 (b)-s (vi} (c) 50 Hz (d} i~o '.,t1Itrr Hz ' '{ '.~' The rule used for finding the directioJtb,r force acting on current carrying conductor placed in magnetic field is: / (a) (b} (c) (d) ;.~fi 1t? Thumb rule Fleming's left hand rule Fleming's right hand rule Faraday's law 2 tr [I l (vii) [I] In a given graph of height vs energy, line AB represents: 8 Enersv A Height (a) kinetic energy (b) potential energy (c) total energy (d) loss in potential energy .~. ' (viii) Alpha particle emitted from radio isotopes are u~ .for: (a) projectiles in nuclear reactions \<,-. (b) to know tp;~j M~~e,~~;~fJ ~e aper "''tt;~. (c) to steriJi e;tn~irled'i~~Fiqtf nt/, :0- -~;,, , .., .. ' \. (d) ckaririg the bloh9 clo"fsIR" fff\ )/j~tlt~~f... ~is,: ' (ix) A '""'v,/; ,, li&h{fi:x is passing from fu'._eflium A to medium B. If medium A is water, then: ,l';/ "<-',f:i;{}}:.. Medium A [I] [I] Normal MediumB (a) (b) (c) (d) (x) Medium B may be air or glass. . Medium B may be air or diiiiih~d. Medium B may be diamond or glass. All of the above Two forces which act in rotation of a body are: (a) One is external force and other is force of reaction at pivot. (b) Called couple (c) Parallel and opposite acting forces (d) All of the above 3 "ji [l] (xi) The diagram shows a coil wound around a U shaped soft iron bar AB. A [l] B What is the polarity induced at the ends A an<I, when the swit~? !~., ~~~~sed? (a) South and south (b) North and north (c) North and south (d) South and north (xii) i~ \ ~ ' 1 ?\<t~. ..' ... \,t,. During refraction we get angle of deviation = L't}{~i when (a) refracted r pes back to same first medium' ~, (b) refracte~U ., . .. al. '"~\\. (c) refract&i (d) re.fi:'-acted ray ben . ./}Tf:s (xiii) \J,; ~ i$J~:i1fi]}f" \. J~ '1~\ 'W! 1t;, :Jtt-Y [l) jtfff{Jil,~\: . \F;.1,;.Lt:}; , . " . .. ,,-.,:.. . (. A o/i.ie~1ttJp.ced in a strong iii~petic field. When a current is passed through the wire it moves up \'ffe;,q~. as shown. "'kt,:;;. 1~tt ~~,; .\ The current is reversed, and the dr(~ tion of magnetic field is also reversed. In which direction does the wire move? (a) Downwards (b) Towards the north pole (c) Towards the south pole (d) Upwards ~ 4 [l] A truck weighing l 000 kgf changes its speed from 36 km/hr to 72 km/hr in 2 min. Its work done will be 5 (a) 1.5 X 10 J (b) 3.6 X 10 5 J (c) 7.2 X 10 5 J (d) 2.5 X 10 5 J [l] Less will be the tenninal voltage in a cell if: (a) Less is the current drawn. (b) More the current drawn. (c) No current is drawn. (d) Constant current is drawn. (xv) [l] " ,~.. 'ttrz ~f~fffji~~lb Question 2 ~ ;1:;. (i) A slab of ice at -50 C is constantly heated till its temperature reaches to 150 C. Draw a graph showing change in temperature with time. Label the various parts of the graph properly. . [3] (ii) A certain sound h,f~ -\::~9 .-;H:f ;2~~-Hz and a wav~~p._gth of l.3t1fift"" ' [2] (a) Calcul{d Mlteis.~ ~wifft,wn~1J ;trir ri,~(..i~~ ; ~ ;-Y ' , . ,.'-,;.. :, 1 ;_ : ::,:.. '>:i,~/\ 1 ay ; '-~ i:, :; (b) What differenoo.,would mt fe1f.ilf .... .the .above sound and -~ ~ther sound ~ Vl?lling at the same spee<(b-~t ~))}\ .. (Hi) '; /~- :, ' i fength 2.6 m? \ Figure shows two isosceles right angle,<1 prisms A anq B and tht? \i_ght ray~ incident on the prism A. Complete the diagram'to show t~e rays emerging out of the pri~. A [2] B \ ''I (iv) (a) State the relation between the critical angle and the absolute refractive index of a . medium. (b) Which colour of.the visible sp~trum has a higher crttical 'angle? \~{ .s ' I '' I ~ I ' i [2] , \f (v) The given figure shows the graph of a conductor at two d"1fferent temperatures. V(volt) t i [2] 1 T hlghtem:. ~ low 2 B temp. l(A) -+ (a) Write with the reason which resistanc ,~,, greater, A or B? (b) How does the resistivity of the eta) micond.m::~pf?J Y.(in.;r;e.lation to . )i;rt:':!ii\ 'E';t~;~ '\,SJ,\"' }1 femJ)erature? (vi) wi;::; ha= :=ha 0 Particle: (b) gains two electrons "-\ , . < '~-1;t ~~,. Qaestio:J;'t:(;,. (i) load of50,000N? A copper w:t{~1"~a ?iameter of0,\ s1!1m and a resistivity ?f 1.6 x 10- 6 .o.. cm. How much of\ _ , would be neo\~fu~ry. q4nake a resistance of IO .o.? .:t~l/~t1.. (ii) :f;; :,. ';" " * (vii) A load M = 500 kg it Fig.2. ... ":~ .:h . in two ciifrerent ways as shown in the given Fig. I and T, T, F"i&-1 Fig.2 F1 and F2 are the forces needed in two cases. Calculate F1 : F2. 6 i)k, [2] [2] [2] [2] [2] Study the diagram below and answer the following questions. L B X A 0 0' L' (a) Name the lens LL' (b) What are the points O and O' called? (iv) Name any two electromagnetic waves which fi~y~a frequency .-~.igh~l ,tP.~ that of violet light. (v) '\J!. "t,/ Explain why one feels ice creant af0 00 ,~lder than water at 0 C? ,;,\',:::;. , .<,,,,, .,, .. Question (i) ' 1:1i~i}t?l~4titf};;tI;!t~~ltti~t1ii!1~:, . . ::;( . 4 . [2] [2] (,ltr,mp~~!;!~"f1t11,1) '"'i)";fll The diagram below shoi sa point source I;-i~;{Jiif? }'.!~iifuiner. The critical angle for [3] waterf~:~urface is 48 . Four rays A, B,C, D starting from the source P are shown upto the w~tef sur:f#ce. AIR WATER A p Pl.th (a) Show in the diagram the of these rays after striking the water surface. (b) Define the phenomenon whic&jhe ray D exhibits. ,q;, (ii) (iii) A piece of ice of mass 40 g is dropped}[nto 200 g of water at 50 C. Calculate the final temperature of water after all the j~~;ffiis melted. (Specific heat capacity of water = 4200 J/kg C, Specific latent hat of fusion of ice= 336 x 10 3 J/kg) (a) Name the S.I unit of physical quantity obtained by the formula 2 Kl V2 . Where K: kinetic energy, V: Linear velocity. (b) A force acts on a body and displaces it by a distance S in a direction at an angle 0 with the direction of force. What should be the value of 0 to get the maximum positive work done? (c) Draw and mention the centre of gravity in a triangular lamina. 7 [3] [4] Question 5 In a single fixed pulley, the velocity ratio is always more than the mechanical advantage. Why? (b) State the energy changes in the following cases while in use: 1. photoelectric cell 2. washing machine (a) {i) (ii) (a) When does the nucleus of an atom tend to ,~ ,riidioactive? A wire of length 80 cm has a freque]}l ~'~f is6''liz. Calculate the length of asimilar wire,iinder similar tension which will have frequency 1024 Hz ~/:_ (b) (ii;) :::::: e:.: :=~:,~s:::~ .:.~z - \ [3] [3] [4] lower two are movable. (a) Draw a tackle to lift the load by . applying the force in downward direction. Mark the position of load and efforts. (b) If the load is raised by 1m, through what distance will the effort move? What is the mechanical advantage of the system? -,tf . Question 6 (i) A ray of light XY passes through a right-angled isosceles prism as shown below. y C 8 (a) What is the angle through which the incident ray deviates and emerges out of the prism? (b) Name the instrument where this action of prism is put into use. (c) Which prism surface will behave as a mirror? ~ 8 [3] 1 water boiling at I i8s e~periment in a . temperature? C m a contain physics lab and is . . er. Explain wh surpnsed when he sees (b) A piece of . y water can boil at the above Wlrehavin . I. How Will g resistance R . . 2. If all the resistance of e:hcut into four equal parts. resistance c Parts are Placed inpart compare with the original resistance? ompared to the resist!iarallel, what will be the equivalent ce of the original wire? (a) (ii) A student perfonn [31 r:: (iii) (a) ( Ali . ~t mass and a hea kinetic energy? vy.mass have momentum. Which will have more [4] (b) How is the radi . . r; ch oactivity of,ffll; l ange to form a chemic~ t - \~ ement a . COtn1>8und? Why? i (c) ~~culate how many al ha '"\i1(1,. 92U decays to zg~Pb and beta P~ ,~les are emitted when urani "',: } - ~rt~:iv. Question 7 (i) (a) LiSt one similarity and one difference between a : ~nt-carrying solenoid and a bar magnet. (b) What is the S.I. unit of m~etic field? ,~,t;, V (ii) {iii) - ::.r,,,, .,, t-::_; :::,,, , ,,:,. -~i;r,t When ~e vehicle is driven, many ti~es its different parts start vibrating, and a rattling sound 1s heard. (a) Why do vibrations start taking place in different parts of the vehicle? (b) Why is there a rattling sound? (c) Name the phenomenon that is observed in this case (b). over long distances voltage is kept very high. Why? (a) During transmission of ed with an electrical appliance rated 2.5 KW, (b) A fuse is rated SA. Can it 200V? Give a reason. c) Name two safety devices whi are connected to the live wire of a household lit ( 1 electric circuit. f.. Question 8 (i) (a) [31 [31 {41 [3] State the work-energy theorem. (b) A uniform meter ruler weighing 10 gf is pivoted at its Omark. 1. What moment of force depresses the ruler? 2. How can it be made horizontal by applying the least force? Calculate the force required. 9 (ii} In the figure given,below, the ammeter A reads 0.3 A. [3] Calculate: (a) The total resistance of the circuit . (b) The value of R (c) The current flowing through R (iii} [4] lar glass slab and through a triangular glass prism. In e two emergent beams differ and why? Question9 , ~-:~,~1,;. (i) (a) You are provided wi ted piece of paper. Using this paper, how will you differentiate between a cbgMt;x lens and concave lens. [3] '\f ;. (b) The human ear can detect coriti;puous sounds in the frequency range from 20 Hz to 20,000 Hz. Assuming that the ~ eed of sound in air is 330 ms for all frequencies, .calculate the wavelengths SQn;jponding to the given extreme frequencies of the audible range. ttf'.'.t'./' (ii) (a) Derive the relation between mechanical advantage, velocity ratio and efficiency of a [3] machine. (b) Explain with an example how a machine can be used to change the point of application of effort to a convenient point. , 10 I I I [4] liii) In the given figure solenoi4 and magnet are placed facing each other._ N S B A (a) Name the parts labelled as Aand B? l d? (b) Why is emf induced during the motio f the magnet or tbe so enoi (c) What will happen if the coil Jd the m same direction? Write wi , on. (d) State the law used to tma.1 ; i~ ftion of the induced emf. .. - 1 /2(,,, - ,:;:f\,\%;~;,., ~ JQ:,}{;r.Y. 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