Physics Questions

A particle of mass m moving in x direction with speed 2v is hit by another particle of mass 2m moving in the y direction with speed v If the collision is perfectly inelastic the percentage of the energy retained by the colliding particles after the collision is close to 1 56 3 35 2 80 4 44

If the refractive index of glass is 3 2 and that of water is 4 3 the critical angle for glass water media is 3 4 A sin sin 86 9 3 2 3 24 32 15 1 B D sin sin 819 45

A metal wire of length L and area of cross section A is attached to a rigid support Another metal wire of length L and of the same cross sectional area is attached to the free end of the first wire A body of mass M is then suspended from the free end of the second wire If Y and Y are the Young s moduli of the wires respectively the effective force constant of the system of two wires is a c X Y A 2 XL Y 4 X Y A 8142 2 124 b d A 44 2 X12 1 2 A 424 1 2

SolveLancer Test A fair die is thrown 8 times Find the probability that a prime number will ap 36b png maximum three times on the throws SolveLancer Test 8 a 90 8 b c d 8 8 93 62

A object is moving parallel to principal axis of a concave mirror of focal length 100 cm Distance between and principal axis is 1 cm The langent of angle between velocity of image and principal axis is nearly A 0 01 C 0 03 B 0 02 D 0 04

If the air of weight w is filled in an empty balloon which weighs w the weight of the balloon will become w Suppose the density of the air inside and outside the balloon is same then A B C D W W W W2 W w w W W Correct Answer W2 W1 W

A non conducting disk of radius 3 m having uniform charge density o 1 C m is rotating with and angular velocity w 1 rad s about its central axis as shown If is magnetic dipole moment associate with the disk and B is magnetic field at centre C then Jo C Bc 2 x 10 7 T 3 m Bc 6 x 10 7 T 81 A m L 81 A m

A motorcycle is moving with a velocity of 6 Okm hr and it takes 8secs to stop after the brakes are applied C alculate the force exerted by the brakes on the motorcycle if it s mass along with the

A thin string is wrapped several times around a cylinder kept on a rough horizontal surface A boy standing at a distance from the cylinder draws the string towards him as shown in figure The cylinder rolls without slipping The length of the string passed through the hand of the boy while the cylinder reaches his hand is A B 2 C 3 D 4

4 An electric dipole of dipole moment P is rotated in a uniform electric field of strength E from position of stable equilibrium to unstable equilibrium Then work done by external agent in this process is 1 Zero 2 PE 3 2PE 4 2PE

Water is flowing continuously from a tap having an internal diameter 8x10 m The water velocity as it 3 1 leaves the tap is 04 ms The diameter of the water stream at a distance 2 x 10 1 m below the tap is close to

In the figure below the coefficient of kinetic friction between the 6 kg object and the surface is 0 2 The force F in N necessary to pull both blocks to the right with an acceleration of 3 m s is Select one O a 88 O b 56 O c 72 O d 40 2 kg 6 kg

Velocity v versus time t graph of a particle moving in a straight line is show tan a tan velocity becomes zero is v m s in the figure If 4 O 2 m s O 3 m s O 4 m s O 1 m s 2 then average speed of the particle till the time its s

PARAGRAPH FOR QUESTIONS 62 64 A box contains a combination of L C and R When 250 V DC is applied to the terminals of the box a current of 1A flows in the circuit When an AC source of 250 V at 2250 rad s 1 is connected a current of 1 25 A flows in the circuit When frequency of AC is increased it is observed that current increases with frequency and becomes maximum at 4500 rad s

A particle moves in the east direction with 15 m sec for 2 sec then northwards with 5 m s for 8 sec Average speed of the particle is A 1 m s 5 m s 7 m s 10 m s

kg block B rests as shown on a bracket A of same mass Constant forces F 20 N and F2 8 N start to act at time t 0 when the distance of block B from pulley is 200 cm Time when block B reaches the pulley is Assume that friction is sent every where Pulley and string are light F A 200cm m B F

A simple pendulum consists of string of length L and suspended mass m It is released from horizontal positi as shown in the figure Speed of the mass when the string becomes vertical will be m www L O 3gL O gL 2 2gL

A diatomic ideal gas is used in a car engine as the working substance If during the adiabatic expansion part of the cycle volume of the gas increases from V to 32 V the efficiency of the engine is ow

24 Two pith balls carrying equal charges are from a common point by strings of equal length the equilibrium separation between them is r Now the strings are rigidly clamped at half the height The equilibrium separation between the balls now becomes NEET 2013 a 1 2 b 3 2 c 2r 3 y 2 d 2r 3

1 67 A particle of mass m and charge q moves along a diameter of a uniformly charged sphere of radius R and carrying a total charge Q Find the frequency of oscillations of the particle if the amplitude does not exceed R Ans 9Q mp 2 4 En

In static electricity which notion is right about the flow of electrons Is it due to electric charge gradient like how air flo ws from higher pressure to lower press ure or is it due to the property of attract ion and repulsion of the charges Are t he charges distributed between the bod ies so as to maintain the highest level o f neutrality

19 Starting from rest if a car accelerates uniformly at the rate of 1 m s for some time and then decelerates uniformly at the rate of 2 m s and finally comes to rest after a journey of 1 minute The maximum possible speed of the car during this journey is 1 10 m s 2 20 m s 3 30 m s 4 40 m s

A block of mass 10 kg is kept at rest on a rough inclined surface as shown The net contact force on m is 10 m s 100 N 80 N O 60 N O 40 N m 0 75 37 Marks 4 1

Two blocks of masses 10 kg and 20 kg are connected by a massless spring and are placed on a smooth horizontal surface A force of 200 N is applied on 20 kg mass as shown in the diagram At the instant the acceleration of 10 kg mass is 12 ms 2 the acceleration of 20 kg mass is

06 A bar produces a lateral strain of magnitude 60 x 10 5 m m when subjected to tensile stress of magnitude 300 MPa along the axial direction What is the elastic modulus of the material if the Poisson s ratio is 0 3 a 100 GPa c 200 GPa b 150 GPa d 400 GPa

9 Assertion A Sea divers wear special suits Reason R There is no effect of gravity under the sea PATH A Both A and R are true but R is the correct explanation of A ab d B Both A and R are true but R is not the correct explanation of A C A is true but R is false D A is false but R is true

In the figure mi has mass 5kg and my has mass 10kg The coefficient of friction between mi and my is 0 5 and the mass my is on the smooth horizontal floor If a force F is applied on the string such that it makes angle 37 with the horizontal then the maximum force F that can be applied so that there is no slipping between masses mj and m2 is 100 x N Find the value of x smooth ITT Q m m 37

A large metallic plate is facing a large charged sheet having charge density per unit area a placed parallel to the plate at a distance from the plate Potential at point P at a distance x from the sheet is kb A 200 C 0 1 x 1 x O A OB O C D 1 x B 260 D 1 x 0

CAREER ENDEAVOUR Problem Consider a two dimensional hexagonal lattice if lattice spacing a 3 and sound velocity c 10m sec The debye frequency w is provide a humerical value in sec D a 1 1x10 3 b 2 2 10 5 c 0 6 10 3 d 1016 S 2

43 Two spheres of masses m and 2 m are separated by distance d A particle of mass is projected straight m 5 from 2 m towards m with a velocity vo Which of the following statements is correct a Velocity of the particle decreases constantly b Velocity of the particle increase constantly c Acceleration of the particle may become momentarily zero d The particle never retraces its path

SolveLancer Test A machine is used to produce magnetic field which creates a magnetic flux number of magnetic field lines when passed through a copper coil varying with time t as p 9 at t Tm The resistance offered by the coil is 9 0 The maximum values of current will be induced in the coil during the interval t 0 to t 3 0 s The value of this peak current will be Here a 4 00 s and 12 00 s 2 SolveLancer Test 3 a b c d a b C 3 A 6 A 4 A 12 A

q a a 2 P X 9 211 200 ZAPOJ 2q 1 What is the electric potential at point P midway between the line connecting the q and q charges assuming that V 0 at infinity ii What is the potential energy U of this configuration of three charges What is the significance of the sign of your answer iii A fourth charge with charge 3q is slowly moved in from infinity to point P How much work must be don in this process What is the significance of the sign of your answer NG

118 The driver of an express train suddenly sees the red light signal 50 m ahead and applies the brakes If the average deceleration during braking is 10 0 ms and the reaction time of the driver is 0 75 sec the minimum speed at which the train should be moving so as not to cross the red signal is 24 355 300 do 65 Sodo 50 m draud est Jog ros Soteri rb d w 3r C o Sob o r k dom do 10 0 ms Sabato d v jodar sodu 0 75 sives san Ja totes ad or jo 30 pardodsys sbs 58 1 27 Km hr 123 7 Kmb 2 115 Km hr 741 83 Km hr

Figure shows a weight of 30 Kg suspended at one end of cord and a weight of 70 kg applied at other end of the cord passing over a pulley Neglecting weight of rope and pulley Find the acceleration of the system and tension in the cord g 10 ms 2 30 kg H T T 70 kg

120 A metal jar has a gas of volume 10 3m at a pressure of 2 x 10 Pa and temperature 400K The jar has small hole and hence the gas leaks into atmosphere The pressure and temperature of atmosphere is 10 Pa and 300K respectively If R is the gas constant the number of moles of the gas that has leaked into atmosphere is 10 m 3035055 2 x 10 Pa bas son 550 88 Ke 35 og Dado leak sob J n n dos b s Sobox 50x 300K Reb o ra grosin se redn 3600 L he 1 1 1 SR 2 6R od 400K e g duider 38 s 10 Pa D van n

Five grams of KCIO yield 3 041 g of KCl and 1 36 L of oxygen at standard temperature and pressure Show that these figures support the law of conservation of mass within limits of 0 4 error

In the circuit shown the power factor of the circuit is Power factor of only RC circuit is Source RMS voltage is 100 volt and its angular frequency w 100 4 5 rad sec RMS current in circuit is 5A If inductive reactance is greater then capacitive reactance then the value of self inductance Lis C H1 L wwww V 100 volt 100 rad sec R wwwwww

Intensity of light 50 Two SHMs in same direction are represented by y asinot and y2 asin ut 8 When they superimpose the initial phase difference of the resultant SHM is 4158 2 28 3 8 10 No 2 Ha K4 s nts

A charge particle having charge qis projected with velocity Vo in the plane of current carrying loop ABCD as shown Magnetic force on charge particle is b 0 qVotole b a 2 ab q Vottole ab qVotole 5 ab b a b a q Vottole b a a

A small bar A resting on a smooth horizontal plane is attached by threads to a point P and by means of a weightless pulley to a weight B possessing the same mass as the bar itself The bar is also attached to a point O by means of a light non deformed spring of length l 50 cm and stiffness k 5 mg l where m is the mass of the bar The thread PA having been burned the bar starts moving to the right Find its velocity at the moment when it is breaking off the plane

he speed of a projectile at its maximum height 1 is 2 times of its inital speed u of projection Its range on the horizontal plane is u 2g 1 3 3u 2g 3u 2 20 2 4 3u g

1 Two identical charged spheres are suspended by strings of equal lengths The strings make an angle of 30 with each other When suspended in a liquid of density 0 8 g cm the angle remains the same If density of the material of the sphere is 16 g cm the dielectric 3 3 constant of the liquid is

The two compounds given below are H H D I Br CI O Enantiomer O Identical O Meso compound O Diastereomers I D CI Br H H

A ball is projected from the point O with velocity 20ms at an angle of 60 with horizontal as shown in figure At highest point of its trajectory it strikes a smooth plane of inclination 30 at point A The collision is perfectly inelastic 20 ms 60 130 A The maximum height from the ground attained by the ball is 15 m The maximum height from the ground attained by the ball is 18 75 m The maximum height from the ground where ball collide on inclined plain is 15m The maximum height from the ground where ball collide on inclined plain is 18 75m

18 In a series L C R circuit R 200 22 and the voltage and the frequency of the main supply is 220 V and 50 Hz respectively On taking out the capacitance from the circuit the current lags behind the voltage by 30 On taking out the inductor from the circuit the current leads the voltage by 30 The power dissipated in the L C R circuit is

119 When a mercury thermometer is inserted in a pot of hot water and the reading is recorded what temperature is being recorded 1 Average temperature of water and surrounding 2 Average temperature of thermometer 3 Average temperature of water and thermometer 4 Temperature difference between water and surrounding

in the figure shown two loops ABCD EFGH are in the same plane The smaller loop carries time varying current I bt where b is a positive constant and t is time The resistance of the smaller loop is Y and that of the larger loop is R Nes the self inductance of large loop The magnetic force on the loop EFGH due to loop ABCD is lab Mn3 X R Find out value of x D B C E H a F G b a

A particle of mass m kinetic energy K and momentum P collides head on elastically with another particle of mass 2m at res Match the following after collision Column I A Momentum of first particle B Momentum of second particle C Kinetic energy of first particle D Kinetic energy of second particle Column II p 3 4P 9 K 9 r P 3 8K 9 s t None

9 A point charge is placed at the center of a spherical Gaussian surface The electric flux phi is changed if 1 Point the sphore is replaced by cube of the same volume the point cage is moved to just outside the sphere the sphere is replaced by a cube of one tenth the volume

Zero Marks 0 In all other cases One coil of resistance 400 is connected to a galvanometer of 1600 resistance The coil has radius 6 mm and turns 100 This coil is placed between the poles of a magnet such that magnetic field is perpendicular te coil If coil is dragged out then the charge through the galvanometer is 32 C Find magnetic field in Tesla