Physics Questions

A block of mass 25kg is suspended to the ceiling by means of light string as shown in figure What is the tension developed in the string A light string is subjected to 25kg

A solid sphere hollow sphere and disc all 23 having same mass and radius are placed at the top of an incline and released The friction coefficient between the objects and the incline are same and not sufficient for pure rolling of any one these Least time will be taken in reaching bottom by 1 Solid sphere 2 Hollow sphere 3 disc fantas 1 2 stellenl 3 f it and at a te num a uni f 84

A disc is placed on the surface of pond with liquid of refractive index 3 A source of light is placed 4 m below the surface What is minimum area of the disc so that light does not come out of liquid O 28 26 m O 42 4 m O 32 62 m O 32 6 m

Three bodies a ring a solid cylinder and a solid 21 sphere roll down the same inclined plane without slipping They start from rest The radii of the bodies are identical Which of the bodies reaches the ground with maximum velocity 1 Ring 2 Solid cylinder 3 Solid sphere A B C S gam a f f 1 R 2 3

5 A cylinder is placed on a horizontal surface A particle is projected with speed u and it crosses the cylinder by just touching at two points as shown in figure If the intial speed with which the mass is projected is 5xm s then the value of x is UA 60 R 0 6m

A thin metallic spherical shell carries a charge Q on it A point charge q is placed at the centre of the shell and another charge q is placed outside it The net force on the charges at the centre and outside are respectively Q q 9 1 Zero towards right 2 Towards left towards right 3 Zero zero I CI 9

A condenser of capacitance 10 F has been charg to 100 volts It is now connected to anot uncharged condenser in parallel The comm potential becomes 40 volts The capacitance another condenser is 1 15 F 2 5 F

21 A tuning fork of 512 Hz is used to produce resonance in a resonance tube experiment The level of water at first resonance is 30 7 cm and at second resonance is 63 2 cm The error in calculating velocity of sound is Speed of sound in air 330 m s a 204 1 cm s c 58 cm s b 110 cm s d 280 cm s

Q 31 Option 1 2 Your Answer 3 Option 2 3 Option 3 4 Option 4 Figure shows two coherent sources S S vibrating in same phase AB is an irregular wire lying at a far distance from the sources S and S Let 10 10 ZBOA 0 120 How many bright spots will be seen on the wire including points A and B d IS I ok of force move from south pole to north pole IS B

In Young s double slit experiment green light with wavelength 5500 is used and 60 fringes were seen in field of view Now sodium light of wavelength 5890 A is used then number of fringes observed in field of view are about O 42 O 48 O 56 072

On a plane mirror a transparent beaker is kept having water upto depth of 8 cm An 4 3 object is kept at a height of 10 cm above water surface How much distance behind the mirror is the image of the object formed 1 16 cm 2 14 cm 3 12 cm 4 18 cm

Two capacitors of capacitance 2 F and 3 F are connected in series The outer plate of the 2 F capacitor is connected to 1000 V source and outer plate of 3 F is earthed The potential of inner plate of each capacitor is O 300 V O 500 V O 600 V O 400 V

The refractive index of glass with respect to water is 9 8 If the velocity of light in glass is 2 108 m s What is velocity in water 2 6 x 108 m s 2 25 x 108 m s O 2 5 x 108 m s O 2 9 108 m s

The current supplied to an air conditioner unit is 7 02 amps The air conditioner is wired using a 10 gauge diameter 2 588 mm wire The charge density is n 8 48 x 1028 electrons m Find th following magnitudes a current density in A m A m b the drift velocity in m s m s

Laser light of wavelength 630 nm incident on pair of slits produce an interference pattern where bright fringes are separated by 8 1 mm Another laser light produces interference pattern where bright fringes are separated by 7 2 mm What is wavelength of second light O 560 nm O 615 nm O 415 nm O 712 nm

44 A person is looking at the image of his face in a mirror by holding it close to his face The image is virtual When he moves the mirror away from his face the image is inverted What type of mirror is he using Convex mirror estion pape 2 Combination of mirror and lens 3 Plane mirror

The eye piece of an astronomical telescope has focal length of 10 cm The telescope is focussed for normal vision of distant objects when tube length is 1 0 m What is magnifying power of telescope 09 0 12 0 15 0 16

Q From the top of a 11m high tower a stone is projected with speed 10 m s at an angle of 37 as shown in figure Find a Speed after 2 s b Time of flight c Horizontal range d The maximum height attained by the particle e X Speed just before striking une ground 11 m 10 m s 37 n

Two small balls having equal positive charge Qeach are suspended by two insulating strings of equal length L from a hook fixed to a stand The whole set up is taken in a satellite into space The tension in each string is O o O C 1 Q 4T 1

The resultant capacitance of n condenser of capacitances C C2 Cn connected in series is given by 09 2012 20 C C C C 02 2 O C C 1 0 C O C C C Cn O C C C Cn

In which of the following circuit is the current maximum just after the switch S is closed i iii E E El R www A i LOGO sv S R S L 000000 R R L R L eeeeee 000000 B ii D Both ii and iii

An electric dipole of dipole moment Pis placed perpendicular to electric lines of force of electric field E then the work done in slowly deflecting it through an angle of 180 is O PE O 2 PE O 2PE

Section b This section contains 15 SINGLE CORRECT TYPE questions Out of these 15 questions candidate can choose to attempt any 10 questions A particle of mass m and charge a accelerate by potential difference Vand enters a region of uniform transverse magnetic field 8 if dis width of region of magnetic field d the angle through which particle deviates is sni Bd 9 2mV

Section A This section contains 35 SINGLE CORRECT TYPE questions Each question has 4 choices 1 2 3 and 4 out of which only one is correct The balancing length for a cell is 560 cm in a potentiometer experiment When an external resistance of 10 n is connected in parallel to cell the balancing length change by 60 cm The internal resistance of cell in ohm is 16 O 14

9 Figure shows a Young s double slit experiment setup The source S of wavelength 4000 oscillates along y axis according to the equation y sin t where y is in millimeters and t is in seconds The distance between two slits S and S is 0 5 mm YA S 0 0 0 5 mm Im 4m vain P DS 8

2 47 Find the mass M in the situation shown in figure 2 212 such that m remains at rest on the front surface of M The coefficient of friction between the front surface of M and that of mis u Ar m M cose M m Figure 2 212 M

19 Two projectiles are projected at angles 0 4 T e with the horizontal where 0 4 4 1 tan 0 1 2 1 tan 0 3 1 1 4 1 3 0 and 3 with same speed The ratio of horizontal ranges described by them is

CUT 18 Velocity of flow of water in a horizontal pipe is 10 m sec Then the velocity head of water will be g 10 m sec 1 100 m 2 10 m 3 50 m 4 5 m 19 The adiabatic elasticity of hydrogen gas y 1 4 at

Two boats A and B having same speed relative to river are moving in a river Boat A moves normal to the river current as observed by an observer moving with velocity of river current Boat B moves normal to the river as observed by the observer on the ground A To a ground observer boat B moves faster than A C To a ground observer boat A moves faster than B C To the given moving observer boat B moves faster than A D To the given moving observer boat A moves faster than B

In single slit diffraction experiment first minima of red light A 660 nm coincides with first maxima of other wavelength A2 What is the value of 2 O 440 nm O 470 nm O 550 nm O 690 nm

Choose 1 A particle at rest can be accelerated 2 A uniformly accelerated motion can revert its velocity 3 In a straight line motion a particle can revert its acceleration without reverting it s velocity 4 All of these

A particle is thrown up inside a stationary lift of sufficient height The time of flight is T Now it is thrown again with same initial speed vo with respect to lift At the time of second throw lift is moving up with speed vo and uniform acceleration g upward the acceleration due to gravity The new time of flight is T 2 C T D 2T A T 4 B

An observer can see through a pin hole the top end of a thin rod of height h placed as shown in the figure The beaker height is 3h and its radius h When the beaker is filled with a liquid up to a height 2h he can see the lower end of the rod Then if the refractive index of the liquid is n 2 find n 3h h

The diagram below shows a lens as a combination of a glass block and two prisms X A B X i Name the lens formed by the combination ii What is the line XX called iii Complete the ray diagram and show the path of the incident ray AB after passing through the lens iv The final emergent ray will either meet XX at a point

et N denote the set of all natural numbers Define two binary relations on Nas x y e Nx N 2x y 10 and R x y e Nx N x 2y 10 Then 1 Both R and R are transitive relations 2 Range of R is 1 2 3 4 3 Range of R is 2 4 8 1 Both R and R are symmetric relations

A point moves with retardation along a circle of radius R so that at any moment Ram and Shyam are walking on two perpendicular tracks with speeds 3m s and 4m s respectively At a certain moment say t 0s Ram and Shyam at 40m and 20m away from the intersection tracks respectively and moving towards the intersection of the tracks A Shortest distance between them subsequently is 15m B Shortest distance between them subsequently is 20m C The time when they are at shortest distance from each other is 8s D The time when they are at shortest distance from each other is 9s

What amount of heat in kJ is required to convert 27 6 g of an unknown solid MM 83 21 g mol at 5 00 C to a liquid at 52 3 C specific heat capacity of solid 2 39 J g C specific heat capacity of liquid 1 58 J g C AHfus 3 72 kJ mol normal freezing point Tf 10 3 C

Q2 A sphere of diameter D which is at a uniform temperature of T is suddenly removed from a furnace and suspended in a large room of air at uniform temperature of T There is a heat transfer by radiation determine the time taken by the sphere to cool to some temperature T k 200 W m K Cp 0 9 kJ kg K D 50mm T 800 k T 300 K T 400 K F 67x100 m K

Q 29 A large spherical mass M is fixed at one posi tion and two identical point masses m are kept on a line passing through the centre of M see figure The point masses are connected by a rigid massless rod of length and this assembly is free to move along the line connecting them All three masses interact only through their mutual gravitational interaction When the point mass nearer to M is at a distance r 31 from M the tension in the rod is zero for m k The value of k is 2015 288 7

8 A beam of light has a small wavelength spread 82 about a central wavelength The beam travels in vacuum until it enters a glass plate at an angle 0 relative to the normal to the place as shown in figure The index of refraction of the glass is given by n The angular spread 80 of the refracted beam is given by a 80 1212862 c 80 tan0 dn n d 82 b 80 d 80 dn 2 d SA sin 082 sin A a 0 80 Vacuur Glass

Two identical pendulum A and B are suspended from the same point The bobs are given positive charges with A having more charge than B They diverge and reach at equilibrium with A and B making angles 0 and 0 with the vertical respectively Then A 0 0 2 B 0 0 C 0 0 1 D Tension in A is smaller than in B A B A B You Missed

17 The diagram given below is of silicon crystal at 300 K Ec E 0 56 eV EF Ev H E E 0 18 eV From the diagram it can be inferred that A The Fermi level is 0 38 eV below the intrinsic level of conduction B The semiconductor is a p type material C The semiconductor is a n type material D E E 0 56 eV

Q19 A solid sphere of uniform density and radius 4 units is located with its centre at the origin O of coordi nates Two spheres of equal radii 1 unit with their cen tres at A 2 0 0 and B 2 0 0 respectively are taken out of the solid sphere leaving behind spherical cavities as shown in the figure Then 1993 Y B the gravitational field due to this object at the ori gin is zero B the gravitational field at the point B 2 0 0 is zero the gravitational potential is the same at all points on circle y 22 36 the gravitational potential is the same at all points on circle y 2 4

Match the columns and select the correct option from the codes given below Column l Column Il i Focal length of convex lens ii Object placed between C and F by convex lens iii Twinkling of a star A i a ii b iii c C i a iii b ii c a Real Inverted Magnified b Due to refraction c Positive B iii a i b ii c D ii a iii b i c

11 A rectangular coil ABCD is placed near a long straight current carrying straight wire as shown What is the net force on the rectangular coil D C 2A 1A V1A 15 cm TEH A 10 cm 2 cm a 35 x 107 N towards the wire c 25 x 107 N towards the wire b 35 x 107 N away from the wire d 25 x 107 N away from the wire

In a LLyod s mirror set up for interference of waves of frequency 6 x 10 4 1 emitted from point source S Distance SO OA AC are 1 mm 50 cm and 50 cm respectively Then the number of dark and bright fringes obtained on the screen will be S 0 O O O Mirror SCREEN C Dark 4 Bright 4 Dark 4 Bright 5 Dark 5 Bright 4 Dark 5 Bright 5

Two trains A and B of length 400 m each are moving on two parallel tracks wit uniform speed of 72 km h in the same direction with A ahead of B The drive B decides to overtake A and accelerates by 1 m s2 If after 50 s the guard of B brushes past the driver of A what was the original distance betw

Electric Charges and Fields 1 With a charge g at the centre an imaginary Gaussian sphere is constructed with a radius r The magnitude of intensity of field at any point on the Gaussian surface is E and the flux through the Gaussian surface is d If we change the radius of the Gaussian surface to 2r what happens to the values of electric field E and electric flux on the new surface A E decreases increases C E increases remains constant 2 ABC is an equilateral triangle of side L A charge q is kept at the vertex A The electric intensity at C compared to that at B has A same magnitude and same direction B different magnitude but same direction C same magnitude but different direction D different magnitude and different direction 3 When two charges each equal to 1q are arranged at the two vertices of an equilateral triangle the mutual force between them is F The magnitude of the electric intensity due to these two charges at the third vertex is 3F A C B E decreases D E increases 4 Two infinitely long thin straight wires having uniform linear charge densities 2 and 22 are arranged parallel to each other at a distance r apart The intensity of the electric field at a point midway between them is 22 r 31 2mcr D zero A not zero but positive C not zero but negative remains constant decreases 2 5 The electric flux expressed in Nm C through a sphere that has a radius of 1 0 m and has a point charge of C at its centre is nearly A 3 6x10 C 3 6x10 B 3 6x10 D 3 6x10 6 A point charge q is located on the x axis at x a and a second point charge q is located on the x axis at x a A Gaussian surface with radius r 2a is centered at the origin The flux through this Gaussian surface is B zero D 2q 8 Next

A particle is projected from the ground at t 0 so that on its way it just clears two vertical walls of equal height on the ground The particle was projected with initial velocity u and at angle with the horizontal If the particle passes just grazing top of the wall at time t t and t t then calculate a the height of the wall b the time t and t in terms of height of the wall

A wave in a string has an amplitude 2 cm The wave travels in the ve direction of axis with a speed of 128 m s and it is noted that complete waves fit in 4 m length of the string Th equation describing the wave is a y 0 02 m sin 15 7 x 2010 b y 0 02 m sin 15 7 x 2010r c y 0 02 m sin 7 85x 1005t 10 IN