Physics Questions

A bomb of mass 3 0 kg explodes in air into two pieces of masses 2 0 kg and 1 0 kg The smaller mass goes at a speed of 80 m s The total energy imparted to the two fragments is 1 1 07 kJ 3 2 4 kJ 2 2 14 kJ 4 4 8 kJ

A block of mass m is attached to one end of a massless spring of spring constant k The other end of the spring is fixed to a wall The block can move on a horizontal rough surface The coefficient of friction between the block and the surface is The block is released when the spring has a compression of 2 mg then choose the incorrect option s k A The maximum speed of the block is g uma m k www m B The maximum speed of the block is 2 g C The block will have velocity towards left during its motion D The extension in the spring at the instant the velocity of block become zero for the first time after m

4 The electric field lines due to two charges A and B are as shown in the figure The ratio of charges on A and Bis B 1 3 4 3 1 2 5 The dielectric strength of air is 5 x 10 V m The 2 3 4 4 4 1

Match the terms of Column I with the items of Column ll and choose the correct option from the codes given below Column l Colu A Diamagnetic 1 Ho Hr 1 a B Paramagnetic 2 1 x 0 0 r C Ferromagnetic 3 0 x E 1 H

A particle is oscillating according to the equa tion X 7 cos 0 5 nt where t is in second The point moves from the position of equilib rium to maximum displacement in time A 4 0 second B 2 second D 0 5 second C 1 0 second

Which of the following options is are true for the given phase transformation curve of the ice water steam system if Q cal s heat is supplied to it Take L 80 cal g L 540 cal g 1 A 4 1 B 1 1 C 1 1 D Cannot relate I and I from the graph T C 100 0 50 S s 1 1 g 9 t s

A coin is placed on a horizontal platform which undergoes vertical simple harmonic motion of angular frequency The amplitude of oscillation is gradually increased The coin will leave contact with the platform for the first time A At the highest position of the platform B At the mean position of the platform C For an amplitude of g m

11 Which of the following statements is true about magnetic field intensity a Magnetic field intensity is the number of lines of force crossing per unit volume b Magnetic field intensity is the number of lines of force crossing per unit area c Magnetic field intensity is the magnetic induction force acting on a unit magnetic pole d Magnetic field intensity is the magnetic moment per unit volum

23 In the given figure a hemispherical object is located in uniform electric field The electric flux through the curved surface is R Radius of the base E 21 DOE

36 Consider the following colour coded carbon resistor The resistance of this resistor is Violet Gold Yellow Red 1 47 10 5 3 81 10 2 20 h 2 47 10 2 10 4 80 10 5

4 ms 28 If gravitational attraction between two points masses be given by F G satellite in a circular orbit will be proportional to b r a r mm2 Then the period of a pr 1 c r d independent of n 29 Suppose the gravitational force varies inversely as

3 20 68 kN C 4 18 88 N C A point charged particle is revolving around a long straight charged wire under influence of electrostatic force If radius of circular path is r then the time period 7 is proportional to 1 MINIL 3 2 r 4 palu

27 Assuming the radius of the earth to be 6 4x106 What is the time period T and speed of satellite for equatorial orbit at 1 4 10 km above the surface of the earth 1 a 6831 s and 7174 ms c 6831 s and 2144 ms 1 b 34155 s and 3204 ms 1 d 2431 s and 3514 ms ravitational attraction between two points masses

A ball of mass m moves with speed v and it strikes normally with a wall and reflected back normally if its time of contact with wall is t then find force exerted by ball on wall 1 2mv t 3 mvt 2 mv t mv 2t

Which of the following forces is not conservative Question Type Single Correct Type 1 2 3 4 F 31 41 F 3x1 4yj F 3y 4x1 F 3x i 4y j Your Answer Status correct

1 Only a 3 Botha and b 2 Only b 4 Neither a nor b Four identical charged particles of charge 1 C 2 C 3 C and 4 C are placed at x 1 m x 2 m x 3 m and x 5 m The electric field intensity at origin is

13 2 In a potentiometer setup when a secondary cell emf 2 V is balanced balance length of 10 cm obtained If another secondary cell of emf 4 V connected in series with initial secondary cell same polarity the new balance length will be 1 10 cm 2 20 cm 3 30 cm

3 q 880 q 16 0 4 30 Two point charges placed at a distance r in air exert force F on each other For the charges force 4F on each other the distance to exert a 1 2r ne shoul 2 2 4 Ar should be Divisions of

A particle executes SHM with amplitude A and time period T At the time t 0 the particle is at its mean position then at what times the particle will have potential energy 50 and 75 of its total energy within t 0 to t T

4 A certain amount of current when flowing in a properly set tangent galvanometer produces a deflection of 45 If the current be reduced by a factor of 3 then the deflection would a Decrease by 30 c Increase by 15 b Decrease by 150 d Increase by 20

slits are of unequal width e slit on screen is four times that only due to the other The screen is placed along axis as shown in figure screen distance between slits is d and that between the lits is D Match the statements in Column I with results lumn II D Column I i The distance between two points on the screen having equal intensities such that intensity at those points is abc d 1 th of maximum intensity 9 O ii The distance between two points on the screen having equal intensities such that intensity at those points is 3 th of maximum intensity int Screen a bcd iii The distance between two points on the screen having equal intensities such that intensity at those points is b Column II D 3d th of maximum intensity 9 mensity b d iv The distance between two d points on the screen having equal intensities such that D d C 2D d 3D d

5 A capacitor of capacitance C is charged up 90 V and then connected to an uncharged capacit of capacitance 2C The final potential differenc across each capacitor will be 1 45 V 3 90 V In a certain region 2 30 V 4 60 V potential is given

In the Figure shown a closed loop carries a current I 600 mA The loop consists of two radial straight wires and two concentric circular arcs of radii 2 00 m and 5 00 m The angle is T 5 The magnitude and direction of the net magnetic field at the center of curvature P is a 3 93 x 10 9 T into the page b 6 98 x 10 T into the page c 1 13 x 10 8 T into the page d 6 48 x 10 7 T into the page

How h 1 2gtxt when the projectile is at same height at di fferent time intervals t o t t ttz 2 h gt t igtitz tmax B u Copex ti T titt 2usine g Rahul Work New Section T t t V total displacemt total time u 0 t t t t ZV copo

20 When a polythene is rubbed with wool it develops a charge 3 2 x 10 7 C The number of electrons transferred is 1 2 106 3 106 2 8 x 1016 4 2 1012

A paramagnetic salt contains 1028 ions m with magnetic moment of one Bohr magneton Calculate the paramagnetic susceptiblity and the magnetization produced in a uniform magnetic field of 10 A m at room temperature Given N 1028 2

Ans 0 9 0 023 micro farad A circuit is shown in the following figure for which C 3 0 011 F C 5 0 01 F and C3 1 0 01 F If C is the equivalent capacitance across AB then C is given by Options 1 2 144 C C C C C 0 9 0 114 F 0 9 0 01 F B

Static friction fs is a constraint force because it prevents relative sliding between contacting surfaces It acts tangentially to the surfaces in contact Hence we call it tangential contact force It is a macroscopic effect of intermolecular forces between the molecules of the surface in contact Static friction basically is an interlocking of the microscopic surface irregularities projection When the surfaces tend to slide fs comes into play The tendency of relative sliding is characterised by a relative acceleration in the absence of friction We can find the relative acceleration a12 and a21 of each surface by as usual process by drawing FBD and writing force equations excluding frictional forces between the surfaces under consideration If the surface 1 has acceleration a12 relative to surface 2 static friction s acts on surface 1 in opposite direction of 12 Similarly 52 acts on surface 2 opposite to 21 Thus static friction opposes the tendency of relative sliding for 1 7

4 A planet of mass m moves around the sun of mass M in an elliptical orbit The maximum and minimum distance of the planet from the sun are and respectively The time period of the planet is proportional to a 7 2 c 1 1 2 b r 2 d r 3 2 1 C the surface of the

103 A voltmeter of 998 ohms resistance is connected to a cell of emf 2 volts having internal resistance of 2 ohms The error in measuring emf will be 1 4 x 10 V 2 2 10 V 13 4 x 10 V 4 2 10 V

20 A resistance of 4 92 and a wire of length 5 and resistance 52 are joined in series and connected to a cell of e m f 10 V and internal resistance 1 2 A Parallel combination of two identical cells is balanced across 300 cm length of the wire The e m f E of each cell is 1 1 5 V 452 ww 3 m E Fo Jor 10 V 1 Q 50 5 m 2 3 0 V

123 The velocity of water waves may depend on their wavelength 2 the density of water p and the acceleration due to gravity g The method of dimensions gives the relation between these quantities as A v k g p B v kg C v kg p where k is a dimensionless D v k 2 g p constant

has a focal length f and power P It is cut into two symmetrical halves b by a plane containing the principal axis The two pieces are recombined as shown in figure c The power of new combination is a b DU c

6 The figure shows the position time x t graph of one dimensional motion of a body of mass 0 4 kg It suffers impulse at regular intervals The magnitude of each impulse is 2 x m 2468 1 0 2 Ns 2 0 4 Ns 3 0 8 Ns 10 12 14 16 t s

Particles P and Q are undergoing uniform h orizontal circular motion along concentric ci rcles of different radii in clockwise sense P completes each round in 2 min while Q doe s it in 5 min time to make one revolution aro und P is

3 20 J 4 1 62 J 2 Consider a small electric dipole of dipole moment p The electrostatic potential due to the dipole at a distance r closer to positive charge on axial line is V and at a distance r on equatorial line is V2 Calculate the value of V V k 1 k 3 Zero gh Work 2 4 2 kp 2 3kp 2 1 40 ATLE

34 The power dissipated across the 302 resistor in the circuit shown is 40 4A JEF 1 30 45 W 302 www www 80 192 ww 2 21 33 W 4 2 W WWW 1622

3 8 A 4 6 A 3 A network of uniform wires is used to form a hexagon of each side 2 cm The resistance of the wires per unit length is 4 2 cm The net resistance across any two adjacent vertices is 1 48 2 15 Q 3 10 Q 4 6 67 2

12 A particle has a rectilinear motion and the figure 12 gives its displacement as a function of time Which of the following statements is false with respect to the motion 1 Between 0 and A the velocity is positive and acceleration is negative 2 Between A and B the velocity and acceleration are positive 3 Between B and C the velocity is negative and acceleration is positive 4 Between C and D the acceleration is positive E SERIES JOINT 34 of farem a fa YA B 4 C an 1 APR 2 Virves 3 BC FICHE

4 L LT and T The inner diameter of hollow metal 6 cylinder is 20 0 5 mm and outer diameter is 210 1 mm then thickness of surface of cylinder with its error limits 1 1 0 6 mm 2 10 4 mm 3 0 5 0 3 mm 4 0 5 0 2 mm 4 L LT 3 T dung 20 0 5 mm 10 1 mm MIT NH CHI HAI 1 1 0 6 mm 2 1 0 4 mm 3 0 5 0 3 mm 4 0 5 0 2 mm

A parallel plate capacitor has a uniform electric fiell E in space between the plates If the distanc between the plates is d and area of the plate is the energy stored in the capacitor is 1 Ad 2 4 E 3 E Ad 60

1 09 A raw egg and a hard boiled are made to spin on a table 09 with the same angular speed about the same axis The ratio of the time taken by the two to stop is 1 Equal to one 2 Less than one 3 More than one 4 Equal to two 271 10 A wheel of radius 20 cm has force applied to as shown in 10 20 cm fx d XY the figure The net torque is af f 8N B N AN 84 N m anticlockwise 2 1 8 N m clockwise 3 2 0 N m clockwise 4 5 4 N m clockwise PCP Sikar 6N 4t 9N Propulsive PTS G I co 80x8xle k 20540 091 1 2 1 1 1 3 unafun BN B30 1 5 4 N m HER 2 1 8 N m funer 3 2 0 N m ferment 4 5 4 N m fernand 2 4 6N AN IIT JEE NEET NTSE OLYMPIADS KVPY

The diagram shows a boiling tube filled with water There is an ice cube wrapped with wire gauze at the bottom of the tube and the water at the top of the tube is heated as shown When water at the top of the tube is boiling the ice cube remains frozen What can you infer from this experiment A Heat gain causes matter to expand C Ice cubes melt at 0 C Ice cube with wire gauze Water Boiling po Bunsen burner B Heat loss causes matter to contract D Water is a poor conductor of heat

3 A hollow metal sphere is filled with water and hung by a long thread A small hole is drilled at the bottom through which water slowly flows out Now the sphere is made to oscillate the period of oscillation of the pendulum A Remains constant B Continuously decreases C Continuously increases D First increases and then d

A particle B is moving in a vertical circle of radius a in anticlockwise direction with constant time period T Another particle A is undergoing S H M on its horizontal diameter with amplitude a and same time period T A is initially at its right extreme and B is at top most point as shown Sun is directly overhead Q 15 At what time does shadow of B first fall on A A 11 00 T B 8 B 7T 8

9 A 4 C charge is placed in some gaussian surface such that outward flux is What additional charge is needed to be placed inside the surface such tha there is net inward flux of magnitude 60 1 6 C 3 28 C 2 14 C 4 10 LC

22 In the figure shown a coil of single turn is wound on a sphere of radius R and mass m The plane of the coil is parallel to the plane and lies in the equatorial plane of the sphere Current in the coil is i The value of B if the sphere is in equilibrium is a mg cos e T R mg TIR c B mg tan e mg sin e

average emt induced in 1 120 V 2 60 V 1 120 V 3 12 V 3 12 V 4 Zero 35 In a series LCR circuit current lags behind voltage then 35 su LCR T 1 C 2 JLC 1 4 w 0 VLC 6 Two identical equiconvex lens of focal length f and 3 11 1 2 refractive index Q 20x1 Fot O are in contact The space between 20 I two lenses are filled with certain liquid If the focal length I 36 1 VLC cu 3 VLC fafen T

In a YDSE let X and Y be the upper and lower slits A thin film of thickness t and refractive index is placed in front of X Let B fringe width The central maximum will shift Only one correct answer A B Downward Upward C Byt 1 i

The two spheres m 1 5 kg as seen in the figure are released from rest and gently nudged outward from the position 0 The spheres rotate in a vertical plane about the fixed centres of their attached gears where the centre distance is d 80 mm apart thus maintaining the same angel for both rods Determine the velocity v of each sphere as the rods passes the position 30 The spring of spring stiffens k 36 5 N m is unstretched when 0 and the masses of the two identical rods of length L 240 mm and the two gear wheels may be neglected Give your answer in m s do not include the units L m e k e 3