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Aniruddha Physics

Aniruddha Physics

Aniruddha Physics

a] In stationary waves, energy is a) uniformly distributed b) maximum at nodes c) maximum at antinodes d) distributed randomly a) claslicily and inertia of the string b) temperature and atmosphe pressure of the string ¢) only on elasticity of the string d) only on volume of the string In stationary wave the disturbance propagates |g Stationary wave of frequency 300Hz a i ae formed in a medium in which the velocity of- a) both x and y directions sound is 1200 m/s. The distance between node _ b) vertical direction only and neighbouring node is 4 c) neither x nor y direction b) Be d) x,y, z direction a) Im 2cm The equation of stationary waves in a string c) 2m d) 4m i with antinode at x = 0 is 9. Onstretched string fixed at both end, P loops | Qnx Ont are formed in length ‘/’ then wavelength will ] a) y = 2asin—— cos Be Qnx _, Int P- P b) y = 2acos—~ sin a). yd b) j c) y=2asin2nxsin2n(n, =n, )t l 2l On yp 4d) d) y=asin—(vt —x) a : 10, When the stretched string vibrates for second In a stationary longitudinal wave, nodes are overtone number of antinodes formed are points of a) 2 b) 3 a) maximum pressure )4 d) 5 b) minimum pressure variation © . . c) minimum pressure 11. In order to increase, the frequency of d) maximum pressure Yrigeon stretched string by 50% its tension must be For stationary wave increased by (keeping its length constant) a) 50% b) 225% y= 2s }estt00n) in CGS units the o) 125% d) 150% 12. In case of forced vibration the amplitude ol distance between node and next antinode is oscillation S a) 8cm b) 16cm a) remains constant c) 4cem d) 2cm in Which of the following is the wrong formula b) decreases linearly for velocity c) decreases exponentially F d) decreases sinusoidally a) Y= Ap jas xp 13. An air column in a tube closed at one end vibrates in unison with a tuning fork of f 1 /T : 1 frequency 331 Hz. If the length of the ai! ice fe d) v=T a column is 25 cm and the diameter of the tube | a is 2.4 cm then the velocity of sound in air at The wave velocity along a string depends on room temperature is { 449 }— =I) : a 340 ni/s ») 350 m/s : ASA SA c) 380s gd 225m Raat rarer air in a pipe closed at woe Pee , ud is u. Haines with a vibrating ttaing bebe of 21. . organ Pipe of See hatte ced of frequency 170 Hz. If the velocity of sound in epee apes 300 m/sec, the two lowest air is 340 m/s, the length of the vibrating air frequencies for the pipe are ue k a) 250Hz,750Hz b) 250Hz, 500 Hz a) 100cm b) 50cm 3) eps 375 Hz d) 125 Hz, 250 Hz c) 300cm ; 4) 25 em 22. ‘Two closed i es when sounded together gave is In Melde's experiment three loops are : 4 weniave, 7 longer pipe has length formed by putting a weight of 8 grams in a 1 m, the length of other pipe is(velocity of massless pan. The weight required to form sound is 300 m/s) two loops is a) 80.5cm » b) 85.4 cm a) 18 grams b) 8 grams <) 94.9 em d) 95.5cm c) 36 grams d) 24 grams 23. A pipe open at both ends gives frequencies 6. What type of vibrations are produced in a which are Sitar wire a) only even multiple of fundamental a) progressive transverse frequency b) progressive longitudinal b) only odd multiple of fundamental c) stationary transverse frequency d) progressive wave | | c) all integral multiple of fundamental 17, In Melde's experiment, 2 loops are formed frequency . on the string is stretched. The string is replaced d) all fractional multiple of fundamental by another string of linear density 16 times frequency that of the first. The no. of loops formed ifall| 24. An open organ pipe has fundamental other conditions are the same frequency 100Hz.What frequency will be a) 2, b) 4 produced if its one end is closed 8! d) 6 a) 100, 200, 300...... 18. In a resonance tube using tuning fork of b) 50, 100, 150, 200, .... frequency 325 Hz, the first. two resonance c) 50, 150, 250, wu... lengths are observed at 25.4 cm and d) 50, 100,200, 300, ...... 774 cm. ‘The speed of sound in air is 25. A tub ; a 5 ih + has a) 318 m/s b) 358 m/s vn ec at both ends has a length of ¢) 338 m/s d) 378 m/s : its internal diameter is 3 cm. The "The minder Qectth oF aie aulijan an air column in that tube in unison with a tuning - " a : ‘ fork of frequency 351.4 Hz is in fundamental resonance tube vibrating in unison with a mode. Then the velocity of sound in air al tuning fork of frequency 320 Hz is 25 cm. If the room temperature is y “ee velocity of the sound in air is 340 m/s then end : correction approximately a) 340 m/s b) 350 m/s a) 15cm b) 4cm c) 330 m/s d) 360 m/s c) 33cm d) 6cm 20. For closed organ pipe resonance occurred when air column has lengths equal to Ar A 3A 5A Oa ars = Cy a cet es 2! 4 - =4' vari 0.5m = 59 _ ZC): Mrorer ea Md os =4 = Pr Also — Hong 15(a): As J, ~ p? - (4-4) -4 q 9 short Aeny T= pT = 2 8= 18 grams, , v(t 1 The weight required to form two loops is 18 “(pt r i} and gms. 16(c): Stationary transverse waves are produced in he l= ay the Sitar wire. Lore 300 ; 1 16 316 P , 16 —— =——+1=—_ 17(c): (%) = Me = OM 16 Lnon 300-300 ' ™ om 300 oo Shon = ae = 0-949 m BR 4 ‘short 316 P Lon = 94.9 cm . = = = The length of the other pipe is 94.9 cm. > P=4xP=4x2=8 23(c): All integral multiple of fundamental 18(c) :v=2n (J - 4) frequency. v= 2x 325 (77.4 - 25.4) 24(c): Frequency produced in pipe open at v= 33800 cm/s = 338m/s both end = 2(Frequency produced in pipe The speed of sound in air is 338 m/s, closed at one end) : 19(a): v= 4n (1+ e) n= 2n, De e= = 3) 95.192 mea 4n 4x 320 100 = 2 -25x107 = 0.265- 0.25 a. = > = 50 Hz. , : Only odd harmonics are present in pipe e =0.015 m=1.5x10" m=1.5 cm closed at one end The end correction is 1.5 cm. wie Ny Dy, -- _. 50, 150, ue 7. : i i t 20(d): For closed organ pipe resonance occurred en one end of pipe is c ose we ge when air column has lengths equal to 25(b) Voceaioe ~~ 150 Hz, 250 Haz, ...... :v=2n . A BAA. = 2x 351-4 (0.48 + 0.6 x 0.03) 4474 = 702.8 (0.498) 21(a): For fundamental mode v=349.99 m/s _¥ _ 300 _ 1000 ¥ =/350 m/s nea 4x03 4 7 250 Hz. The velocity of sound in air at room ‘ temperature is 350 m/s. For first overtone n, =3n=3 x 250=750 Hz, The two lowest frequéncy of the pipe are = 250Hzand 750Ha tri = c= Ete] Pierce ~ MAbWETLC FIELO qoe To WKREW T- Teatel = 25 ~ 6. “I The lines of force around an infinitely long conductor carrying current are a) perpendicular to the conductor b) inclined to the conductor c) parallel to the conductor d) concentric circles How many number of turns of circular coil of radius 12.56 cm and current 1 A produces the magnetic induction of 5 x 10° tesla at its centre a) 5 b) 15 c) 10 d) 20 In the equation of Ampere's circuital. law ie (Bd =n,1, current I through a closed path is , ; a) net current b) sum of all current c) product of all current d) D.C. and A.C. current Maximum kinetic energy of the positive ion in the cyclotron is (| q’Br, qB’r, a) 2m _ b) 2m , q' Bir? ) q’B’r? . 2m 2m’ The_-fréquency of proton produced by cyclotron in a magnetic field of induction IT is a) 15.26 MHz b) 1.59 MHz c) 1.00MHz d) 159 MHz The range of ammeter can be increased by a) decreasing shunt b) changing scale c) increasing shunt d) removing shunt In a current carrying long solenoid, the field produced does not depend upon a) number of turns per unit b) flow of current c) radius of solenoid d) permeability of medium 8. 10. x10'Q. The new A voltmeter of resistance 5 the range series resistance required to increase three times a) 10°Q c) 10'Q ‘A solenoid of length 1. having 10 turns perc 2 flowing through it. The magneti at axis inside the solenoid is a): drt x10°G b) 40 x10°T c) 2n x10°G d) 22 xlO"'T A M.C.G. will be more sensitive if its suspension strip is a) long and thick c) short and fine The accuracy of M.C.G. can be measured in terms of b) 1032 d) 1022 5 mand 4 cm diametr m. A current of 5 A c induction b) long and fine d) short and thick b) vollage a) current c) sensitivity d) error A moving coil galvanometer gives full scale defletion when a current of 0,005 A is passed through its coil. ILis converted into a vollmeter reading upto 5 V, by using an external resistance of 975Q. ‘The resistance of the galvanometer coil is a) 302 b) 402 c) 252 d) 502 In M.C.G. a current of 2A° for radial magnetic ficld 4x10 Whb/m? produced some deflection. If the field is doubled by keeping all the other quantities same, the current for same deflection will be a) O.5A b) 3A _c) LA d) 15A " Arectangular coil of wire of 100 turns each of area 10 cm* hangs freely in a radial magnetic field of 200x 10° Wb/m?. When.a current of 5 mA is passed through the coil, the coil is deflected through an angle of 60”. The torsional constant of the suspension fibre is | rr region Conductivity of semiconductor c) only one fourth cycle of the input signal 1. ) increases with increase in (emperature d) less than half but more than one fourth a ma : b) decreases with increase in temperature cycle of input signal b a all bz ci ) always increases with addition of | 9: Solar cell based on the principle of ¢) impurity a) photo-voltaic effect d) always decreases with addition of b) reverse biased effect impurity c) thermo electric effect y Semiconductors of both p-type and n-type are d) photoelectric effect : “ produced by 10. Light emitting diodes emits light when it is in a) ionic solids b) metallic solids a) forward biased — b) reverse biased ¢) covalent solids d) coordinate solids c) zero biasing d) infinite biasing 3, ‘The current of a p-n junction on increasing | 1], LEDs of GaAs and GaAsP releases energy in reverse bias to a large value, will a) infra-red and visible region respectively a) increases b) decreases b) visible and infra-red region respectively c) remains same d) suddenly increases c) visible and ultra-violet region respectively 4. In pn junction diode, if junction current is d) ultra-violet. and infra-red zero, it means that respectively a) no potential barrier 12. Emitter is heavily doped because b) number of majority carriers and minority a) to produce a large number of majority carriers crossing the junction are equal carriers c) number of majority carriers exceed the b) to produce a small number of majority minority carriers crossing the junction carpiers d) number of minority carriers exceed the c) depends upon temperature majority carriers crossing the junction it is a semicond - device 7 < . . dibdodors tobey Ohm's law d) itis a semiconductor device 7 ier fode tore nr - me 7 a ‘bine 18. The arrow head on the transistor symbol dhecantce ticis nature “on fomwa . always points in the direction of aracteristic is : : ‘ a) electrons flow in the emitter region a) linear b) sinusoidal ; . , b) holes flow in the emitter region c) non - linear d) hyperbolic an — : : 6. Zener dieda warkon o munony Sates a the emilier repion a) zero bias b) forward bias a 7 majorily carrier in the emitter region ©) reverse bias d) infinite bias 4. Inn-p-n Gansistor current is directed from 7 Power gain is highest for a) base to emitter —b) base to collector a) CB transistor b) CE transistor c) emitter to base — d) emitter to collector i and |. is c) CC transistor d) same in all transistor 15. The correct relation between I,,, I, and §, is 8. Ina full rectifier the current in each of the a) I. Et diodes flow for c) I,<1.1,>1, a) the complete cycle of the input signal 16. Current gain in CB configuration is less than b) half cycle of the input signal unity because . {518 °F “a 1. a) >, b) I<, ) I>], . d) 1,>1, One prefers to use transistor in common emitter configuration, because a) current gain is small b) safe to operate c) less expensive ) d) the current gain is very large and hence the power gain increases In a p-1-n transistor emitter current is 11mA and collector current is 8 mA, Then the base current is a) 8mA b) 3mA c) 19mA d) 1lmA For a common emitter current gain is 80. If the I, =9 mA, then base current will a) 1/81mA b) 8mA c) V/8mA d) 1/9mA The current gain of the common -base n-pn transistor is 0.96. What is the current gain if it is used as common emitter amplifier a) 16 b) 24 <) 20 d) 32 For a transistor amplifier, which is not defined a) energy gain b) current gain c) voltage gain A combination of AND function and NOT function results in a) NAND gate b) NOR gate c) OR gate d) NOT gate Which one represents the symbol of an AND gate A a yy bja— >O YY B : A : A ) TO a —>~ The following truth table corresponds to the logic gate d) power gain a) AND b) NAND c) OR d) NOR Which one of the following represo correctly the "uth table" of 4, configuration shown in figure below Ae Be a) [A 519 “The dimensional formula Newton’s law of gravit because it a) is always attractive b) acts on all masses at any distan : c) is affected by the medium Sle d) does not act on al] m distance The gravitational force betw bodies is a) depends on nature between two bodies b) independent of the other bodies ation is Universal asses at any Presence of the c) depends on the Properties of th between them ied d) depends on the Presence of the other bodies ~ i oI for the gravitational constant is |: Ney a) MLT~ b) M“L!T= c) ML?T2 d) M'L'T2 If the distance, between Sun and Earth is doubled, the gravitational force between them will become | a) double c) four times b) half d) one fourth As we go from the equator to the poles, the value of ‘g’ a) remains same b) decreases c) increases : d) first decreases then increases The mass of the particle at the centre of Earth, where acceleration due to gravity is zero, is a) zero ~ b) « c) greater than at pole d) same as at other places een two of medium “10. 12. 13. UV SEA The S.1 unit of G/g is a) kg/m? b) kg/m c) m/kg d) m’/kg At what height from surface of Earth the value of acceleration due to gravity will become half that on the surface of the Earth (R, = 6400 km) a) 2725km b) 2928 km c) 2650km d) 2524 km The value of acceleration due to gravity on the surface of the Earth is 9.8 m/s’, what is the mean value of density of Earth? (G=6.67 x 10"! Nm?/kg?, R = 6400 km) a) 5.5 x 10% gm/cm? “b) 5.5 x 10* kg/m? c) 0.55 x 10° gm/cm? d) 0.55 x 10° kg/m? As the height of satellite decreases its critical velocity a) increases b) decreases c) remains same d) first decreases then remains constant The ratio of the orbit speeds of two satellites round the Earth is 3 : 4, The ratio of their orbital radii is, a) 16:9 b) 9:4 c) 4:9 d) 3:16 If a body describes a circular motion under inverse square field the time taken to complete one revolution. T is related to the radius of the circular orbit as a) Tar. b) Tar? d) Par d) Ta ot é If the distance between Earth and Sun is doubled, then the new period of rotation. ; of Earth around the Sun will be a) 51.829 days b) 109 years. c) 1290 days d) 1032 days 14. 15. 16. 18. 19. 20. The magnitude of the total encrgy or body in orbit is equal to the magnitude © a) potential energy b) kinetic energy c) 1/2 (K.E.) qd) PE.+KE. ' : Binding energy of a body revo ving in eivulay ehbitat height 1/2 from Earth’s surface is a) GMm/2R b) GMm/3R c) 2GMm/R d) GMm/4R The kinetic energy of a satellite in an orbit close to the Earth is E. What should be its K-E., so that it escapes from the gravitational field of the Earth a) E/2 b) 2E c) E d) EA If the horizontal velocity is’ greater than critical velocity but less than escape velocity, the satellite will move in a) circular orbit b) an elliptical. orbit c) tangential path d) parabolic path The escape velocity for a body projected vertically upwards from the surface of the Earth is 11.2 km/s. If the body projected in a direction making:an angle of 30° with vertical the escape velocity will be ’ a) 11.2xsin 30 km/s b) 11.2 x cos 30 km/s c) 11.2 x tan 30 km/s d) 112km/s A satellite is revolving in a circular orbit around the Earth with the speed equal to half the magnitude of escape velocity | from the Earth. The maximum height | attained by the satellite above the Earth surface will be a) R b) R/2 c) 2R d) R/3 What is the escape velocity fre surface of the planet of radius 2 21. 22. 23. 24, 25. “the accele ‘b) opposite direction as that of Earth’ | Gravity, , ration due to gravit > on anet is 2.5 m/s2 the a) 12 km/sec 5 22 kin/sec ¢) 3.2 km/sec 4d) 4.2 km/seg ‘The ratio of the radius of a planet that of planet Bis r. The ray, acceleration due to gravity on the py of ig x, The ratio of the escape velocity fog the two planets is surface of the pl a) xr b) Jx7r e) 7x d) ex The ratio of the radius of the Earth tg th of the Moon is 10.7. The Tatio of re acceleration due to gravity on the Bart, and on the Moon is 6. Then the ratio of the escape velocity from the Barth’, o that from the Moon is * surface t : a) 10:1 b) 6:1 c) 8:1 d) 1.6621 If the Earth rotates faster that its Present speed, the weight of an object will increases at the equator but remains unchanged at the poles b) decrease at equator but remains unchanged at the poles c) remain unchanged at the equator but decreases at the poles d) remain unchanged at the equator but | increases at the poles | The geostationary satellite is one which | revolves around Earth at a suitable height a) _ with a) same velocity as that of Earth's | rotation about its axis rotation about its axis. ‘ c) different direction of Earth's rotation | about its axis velocity as that of Earth’ n about its axis Seti ncn caren — oy, Fiscape velocity 1§ Jndependent of aig 1 Jes " Clog,” 184): Fe projection there City 14(d): 15(b): 16(b): 17(b): T, = 2V2T, = 2V2x1 =2x 1414 = 2.828 years = 2.828 x 365 days T,, = 1032 days The new period of rotation of Earth around the Sun is 1032 days. The magnitude of the total energy of a body in orbit is equal to the magnitude of PE+K.E. GMm BE-_GMm __GMm__ 2(R+h) n+) 3R 2 GMm ; K.E.= ——— = R+) (R+h=R) KE.-SMm p= GMm 2R..” 2R 42 Kb=Lmv? =m] 2OM R fo SM 2 Ro K.E.<2 x 9Mm 5p IR If the horizontal velocity is greater an critical velocity ‘but less thane: velocity, the satellite will mov elliptical orbit... : 11.2 km/sec: Ve 19(a): ver D GM _! 26M gah 2VoR 2GM OM 2h ya R+h 4 Lives Rt+h 2R R+h=2R " wpeaQR-R=R The maximum height attained b satellite above the Earth surface is R, vy, =, |ge = f2%2-5%2% 10" = YL0x 10° = 3.162x 10° m/s 20(c): ov, = 3.162 10°m/s = 3.2 km/s The escape velocity from the surface of : the planet is 3.2 km/s Ra, Ba 2d): Se =net=x 21(d): Ra By | Wen - [Ra Ba = ix | (vy Ro £5 i The ratio of the escape velocity from the | : two planets is rx + | 22(c): v, = [Bey Re Bm Re escape velocity from tface to that from th? f ji g'=8— Ro? cos’9 93(b . me’ = mg —- mRw? cos’9 At equator 9 = 0, cog = 1 *, mg’ = mg - mRw? ( At poles, 8 = 909 +. mg' = mg . If the Earth rotates faster that its present speed, the weight of an object will decrease at equatoy but remains unchanged at the Poles Weight decreases) > COs 90 = 9 Gravitation ): The geostationar 9A(a): revolves around with same velocity and ins as that of Earth rotation, Y Satellite is 9 Earth ata sui me which table height ame direction 95(d): The synchronous Satellite orbits from west to east in equatorial plane. _ ae) eee me In SI, the consta, law of magnetis; nt of proportionality mM is (for vacuum) Bo 1 in the inverse square a) = An dn Anh, c) hy d) dnt, The formula for ma, ? netic i i atan axial point is Bt nduction due to ashort magnet Hy 2M ty) M Var YES g Me 2M y nM The magnetic indueti Toh Mee Agnetic induction at axial point is equal to , S B, a) 2B.) a °) 3B, a) Be The torque acting on a bar i : ! a magnet a) MBsin® b) Bsing c) MB cout d) Beos@ A bar magnet has poles stron aparts. What is the magnetic Pon sarki a) GAm? b)3 : ent of the magnet ) 3 Am c) 12Am? 2 A bar magnet has poles str tn Who oem : Poles strength 48 Am. Which are 25cm a part. Ww hat torque is required to hold this magnet at an 30° which a uniform field ‘of flux density 0.18 T. Tf its magnetic moment is 12Am? a) 0.3Nm b)0.6Nm_ ¢) 0.9 Nm Which of the following is most suitabie mate electromagnet : a) steel b) softiron c) copper d) nickel A short bar magnet placed with its axis at 30° toauniform magnetic field of 0.2 T experience to torque of 0.6 Nm. Calculate the magnetic moment of the magnet a) 12Am? b)3Am?— c) 9 Am? d) 6Am* A bar magnet of magnetic length 0.1 m and has pole strength of 10 Am, calculate the magnetic field ata distance of 0.2 m from its centre at a point on its axis a) 25 x 10° Wb/m b) 2.5 x 10% Wbh/m c) 0.025 x 10“Wb/m d) 0.25 x 10 Wb/m . A short magnet has a magnetic moment of 30 Am’. If its magnetic length is 10 cm, calculate its pole strength. a) 60Am_ b) 300Am_c) 120Am d) 150 Am A bar magnet has pole strength 10 Am and magnetic moment 2 Am?. Find the magnetic length of magnet. a) 10cm b) 20cm c) 25em d) 30cm ich are 25 cm d) 0.12Nm vial for making 12. The material of electromagnet has a) high retentivity, low coercivity b) low retentivity, high coercivity c)_ low retentivity, low coercivity d) high retentivity, high coercivity . The magentic induction at axial point is 4.8x10°Wb/m’. The point is on same distance on the equator as that of axial. The magentic induction at that point is a) 2.4 x10%T b) 2.4 x10*T } cc) 2.4x10°T d) 24x10°T - A short bar magnet has a magnetic moment of 3 Am*. Determine the megnitude of magnetic induction at axial Point at a distance of 40 cm from its centre. 17. 21, 16. 18. 19. 20. 22. 23. 24, 25. a) 2.5 x10 'Wb/m? b) 1.5 x10 fm? c) 1x10} Whb/m’ d) 2.5 %10°Wb/m? At what distance along the equator of a short magnetic dipole is the magnitude of magnetic induction due to the dipole the same as that at a distance of 10 cm along the axis of the dipole a) 7.94cem b) 8.94cem c) 6.94cm d) 9.94 cm A freely pivoted magnetic needle is subjected to a horizontal eastward magnetic field, due to which it rotates through 40°. If the horizontal component of earth's magnetic field is 0.36 tesla, calculate the induction due to the applied eastward magnetic field a) 0.302 tesla b) 3.02 tesla c) 0.0302 tesla d) 30.2 tesla The horizontal components of the earth's magnetic field is 2.8 gauss and its vertical component is 0.2 gauss. Then earth's total magnetic field at that place is a) JB gauss b) 2y% gauss c) ./3 gauss d) 3/2 gauss The ratio of magnetic induction at axial and equatorial point when the distances are 2.4 cm and 3.0 cm respectively a) 5:4 b) 4:5 c) 64:125 d) 125: 64 The maximum torque experienced by a bar magnet placed in a uniform magnetic field, of induction 3.2 mT,16 x 10-* Nm. What is the magnetic moment of the magnet ? a) 5Am?- b)4Am? cc) 6 Am? d) 7 Am* ‘A long magnet has a magnetic moment of 4 Am? and magnetic length 40 cm. Find the magnitude of the magnetic field induction on the equator 60 cm from the centre of the magnet a) 18.51 x10? Wb/m? b) 1.851 x 10-7 Wb/m? c) 185.1 10-77 Wb/m? — d)_ 0.1851 x 10-7 Wb/m* The pole strength of a magnetic pole is 1 Am if it repels an identical pole 1 m away with a force of a) IN b) 4nN ©) 107N d) 4nx107N A short bar magnet has magnetic moment of 0.485 Am?. Find the magnetic field produced by the magnet at 10 cm. from the centre of magnet on equitorial line of the magnet. a) 48x 10¢T b) 0.485 x 105 T c) 4.85 x 10°T d) 48.5 x 10°T If the magnetic length of the magent is 25 mm its geometric length will be a) 10cm b) 40cm ce) 38cm d) 30cm Find the pole strength of magnet having magrietic moment 250Am?and geometric length 6cm. a) 500 Am b) 4000 Am c) 6000Am_ d) 5000 Am Magnetic moment of an atom is the a) vectorsum of orbital moment and spin moment of electron b) equal to orbital moment of electron c) equal to spin moment of electron d). neither 'a' nor'b’ { 292 = Xt] 26. 27. 28. 29, 30. Electromagnet are used in a) electric bells b) loudspeakers ¢) both'a' and'b d) neither 'a' nor'b' Electromagnet are made up of a) diamagnetic material b) paramagnetic material c) ferromagnetic material d) both'a'and'b’ Atany places a vertical plane passing through the magnetic north and south of the earth is called a) magnetic meridian b) magnetic equator c) magnetic axis d) geographic meridian The angle between the magnetic meridian and geographic meridian ata place is known as a) geographic axis b) geographic equator c) magnetic declination qd) magnetic axis Two short magnets are placed as shown and are restrined so that they cannotrotate, At point P, on thier common equator and equidistant from both sthe magnitude of the magnetic field induction is N s N s c) B,-B, do Answer key a) 5 ©) c 2 (a) 3 (a) 4 5 ¢ A c 7 a 8 (dd) 9 -(b) 10 (b) 1(b) 12 () 13°) «4 (5 @) 16 (a) 17 b) 18 @) 19 @) 20 fa) 21 fd) 22 () 28 fa)’ 24 (a) 25 (a) 26(c) 27 (c) 28 (a) 29 (<). 30 (a) 293 _} F will be Fe te cuit i . The increase 1n length ire 1 A body which completely regains its original weight of 2 kg igor the material of the wire dimensions when deforming forces are (Young O! N/m - ok removed is called = 2% F “. b) 918 x 10°m a) elastic bod: a) 9.8 x 10'm ly 8x 102m d) 1.* 10°m ae b) plastic body” c) 19.8 x i rial, | PI y ires A and B are of the samme m a c) perfectly elastic body 7. Two wires Aa in the ratio-1:2, ra ein} d) tigid bod: their lengths are in the ratée é force, | ee Ri a: ee le of nearest the ratio 2:1. If they are pulled by s be in the 2 7 ich - is the exdmp ¢ oF nean then their increase in lengths will be i PP . ratio a) perfectly elastic body a) 1:2 b) 2:1 b) perfectly Plastic body °) 8. 1 d) 1:8 | ¢) Partially Plastic body 8. Two wire having same material have radii in|] d) partially elastic body 7 the ratio 1:2and lengths in theratio 1:4. 3. Which of the following graphs of load against If extensions produced ate equal, then the oe represent verification of Hooke's ratio of loads applied HAW) mg di a) 1:1 b) 4 Extension Extension c) 2:1 d) 4:1 a) b) 9. Two wires have same material and same } length but ratio of their radii is 1 : 3. These o| are stretched by force F, and F, respectivel ton oy to produce equal elongation. The ratio of F. Load : and F, is L : . ; 9:1 b) BO Extension d) Extensio: a) : c) Lensio 1) Extension °) _ 4) 1 me 10. The symbols Y, n aild K represent “ respectively the Young's modulus, rigidil Load ce) aa modulus and bulk modulus. If rigidit on modulus is three times the bulk modulus 4, Young's modulus of a substance depends then : upon a) Y=4.5K b) Y=3.5K a) its area 9 18 b) acceleration due to gravity oc) Ye 3K d) Y= =k ture of material = 7 alec 1. When a liquid of volume 5 litré is subjected i , Soe to an additional pressure of 5 x10’N/m:, the ; ‘ » th i P off m’, 5. With stress 5 x pie pale a ori length change in the volume is found to be increased by 0.1 Yo of origmal feng} 5 ml, the bulk modulus of the liquid is value of Young’ eae s oO N/m a) 5 x10" dyne/em? a) 5x 10°N/m’ —b) o* l na b) 15 x10" dyne/em? c) 5x10" N/m? d) 5x 108N/mt e) 5x10" N/m? 6 A wire having a length of 100 cm and area of d) 5 x10" N/m? cross section. equal to 1 mm‘ is stretched by a (ae leas Pressure required to reduce the volume of a olid to half of its initial volume is P. Bulk modulus of the material should be a) P b) 2P ec) P/2 d) 4P For perfectly rigid body, value of 1 is a) co : b) 0 ‘ c) 1 d) non negative finite constant A metallic cube whose each side is 10 cm is subjected to a shearing force of 2100 N. The top face is displaced through 0.25 cm with respect to bottom. The shear modulus will be “ a) 8.4.x 10°N/m? b) 525 x 10+ N/m? c) 52.5 x 10'N/m? d) 5.25 x 107 N/m? The theoretical limiting value of Poisson's ratio lies between a) -1to 0.5 b) 1 to 0.5 c) -0.5 to +1 d) -1 to0 A 3 m long steel wire is stretched to increase in length by 0.3 cm. Poisson's ratio for steel is 0.26. The lateral strain produced in the wire is a) 0.26 x 107 b) 0.26 x 10°! c) 0.26 x 103 d) 0.26 x 10+ After plastic flow of stress-strain curve, the stress corresponding to which the wire breaks is called as a) elastic limit b) breaking stress ___c) yield point d) none of these 38. The particular point on the stress-strain curve E at which the strain begins to increase even without a change in stress, is called as a) yield point b) elastic limit c) permanent set region d) breaking point The following graph shows stress - strain curve for a metal wire, the part in which Hooke's law hold good is a 20. 21. 22. 23. 24, 25. “aE a) OA b) AB c) CD d) BC To avoid error due to bendin a) the two wires are su different supports b) the two wires are suspended from the same rigid support 8 Of suppox, spended from c) M.S.G. is rotated in clockwise direction d) the two wires used are of different materials To eliminate error due to kinks in wire, which of the following is correct a) two wires are of same material are hanged from different supports b) position of air bubble is adjusted to one side c) a dead - load is applied to reference wire and zero load to experimental wire £ OW MTODy d) a load beyond elastic limit is’ applied to experimental wire The property of metals which allows to form a thin wires beyond their elastic limit without rupture is a) ductability b) malleability c) elasticity d) hardness When the load suspended from the end of a wire is increased from | kg to 6 kg the extension produced in the wire increases from 0.5 mm to 3 mm. The work done during extension of the wire is a) 8.575 x 10°J b) 8.575 x 10°] c) 8.575 x 10-°J d) 8.575J A steel wire of 4.0 m is stretched through 2.0 mm. The cross-sectional area of the wire is 2.0 mm*. If Young's modulus of steel is 2.0 x 10'' N/m’, the energy density of the wire is a) 2.5x 10'J/m? —b) 2.5 x 10°J/m* c) 2.5% 10%J/m? — d) 2.5 x 108J/m* Strain energy density of wire is 0.1 J/cm’. If the strain on the wire is 0.1 then the stress in it is a) 12 x 10°N/m? c) 2x 10*N/m? b) 2x 10°N/m? d) 2x 10'N/m* = =~ 319