Physics Questions

Gravitation 39 3 An artificial satellite is moving around earth in a circular orbit with speed equal to one fourth the escape speed of a body from the surface of earth The height of satellite above earth s surface is R is radius of earth 1 3R 3 7R 2 5R 4 8R 4 Which graph best reproconto

A person is throwing two balls into air one after another He throws the second ball when first ball is at highest point If he is throwing one ball every second how high do they rise g 9 8 ms2 2 45 m 4 9 m 9 80 m 19 6 m

lo d b Figure 4 48 Coaxial cable with off centered inner surface of the outer conductor for Problem 4 37 4 38 Force and torque on a triangular current loop A rigid loop in the form of an equilateral tri angle of side length a is situated in a uniform steady magnetic field of flux density B The magnetic field lines are parallel to the plane of the loop and are perpendicular to one of its sides as shown in Fig 4 49 If a steady current of intensity I is established in the loop find a the force and b the torque on each of the loop sides as well as c the net force and d the net torque on the loop The current with the dot is positive while the Current with the x is negative

Two beams A and B of plane polarized light with mutually perpendicular planes of polarization are seen through a polaroid From the position when the beam A has maximum intensity and beam B has zero intensity a rotation of polaroid through 30 makes the two beams appear equally bright If the initial intensities of the two beams are I and I respectively then I I equals a 1 3 c 3 2 b 3 d 1

126 A proton accelerated through a potential dif ference of 100V has de Broglie wavelength 20 The de Broglie wavelength of an a par ticle accelerated through 800V is 20 A 2 C 20 4 20 B 2 D 20 8

move apparent frequency equal to 11 12 of the original frequency 1 V 2 2 2V 3 V 4 4 V 11 31 A whistling engine is approaching a stationary y observer with a velocity of 110m s The 44 velocity of sound is 330m s The ratio of frequencies as heard by the observer as the engine approaches and receedes is 1 n 10n 2 n 03 n 0 In 4 n 0 In a source of sound is travelling towards stationary observer The freqency of sound heard by the observer is 25 more than that of the actual freqency if speed of sound is V that of the source 2 4 1 1 4 3 3 3 6 is 4 2 1 1 V 5 2 V 4 3 V 3 4 V 2 38 Two aeroplanes A and B are moving away from one another with a speed of 720 kmph 45 A truck blowing horn of frequency 500 Hz travels The frequency of the whistle emitted by A is 1100 Hz The apparent frequency of the whistle as heard by the passenger of the aeroplane B is velocity of sound in air is 350 ms towards a vertical mountain and driver hears echo of frequency 600Hz If velocity of sound in air is 340m s then speed of truck is 1 31 m s 2 41m s 3 51m s 4 21m s KEY 1 300Hz 2 400Hz 3 500Hz 4 600H 39 An engine is moving on a circular path of radius 100 metre with a speed of 20 metre per second The frequency observed by an observer standing stationary at the centre of circular path when the engine blows a whistle of frequency 500 Hz is 1 more than 500 Hz 2 less than 500 Hz 3 500 Hz 4 no sound is heard perceives the sound n n If the velocity of sound in air is 300 m s then 40 The frequency of a radar is 780 MHz The frequency of reflected wave from an aeroplane is increased by 2 6KHz The velocity of the aeroplane is 1 2 km s 2 1 km s 3 0 5 km s 4 0 25 km s 41 An observer moves towards a stationary source of sound with a velocity one fifth of the velocity of sound The percentage increase in the apparent frequency is 1 5 2 20 3 zero 4 0 5 4 A train is moving at 30ms in still air The frequency of the locomotive whistle is 500 Hz and the speed of sound is 345 ms The apparent wavelengths of sound infront of and behind the locomotive are respectively 1 0 63 m 0 80 m 2 0 63 m 0 75 m 3 0 60 m 0 85 m 4 0 60 m 0 75 m 1 2 7 1 13 3 19 4 25 2 31 1 37 4 43 2 43 A vehicle with a horn of frequency n is moving with a velocity of 30 m s in a direction 2 3 2 k 2 1 3 3 4 2 5 1 6 4 8 2 9 1 10 2 11 2 12 1 14 2 15 2 16 1 18 2 22 2 28 3 34 1 40 3 20 1 26 1 32 3 38 1 44 1 y Acos 2ant 22 21 3 27 2 2 V part max GR IFF MAINS MATERIAL 33 4 39 3 45 1 HINTS V n 270x 2 17 4 23 3 29 2 2TX cos 2n 2n 2 2 Ap 1080x 35 4 41 2 Use cos 0 a y 6m 2 sin 2n 31 x 24 2 30 2 36 4 42 2 1 cos 20 2 3 x N2 N where N is no of waves and V n n 4 Vwave A 4 na T 6nrad Ab 180 2 n V Ax AMARAVATI IT JEE ACADEA

the equation of trajectory of a particle in bx2 where a and b vertical plane is y ax are positive constants then angle of elevation of highest point from the point of projection is 1 tan a 2 tan 1 3 tan b 4 tan a N O NI 2 b 2

A spring of force constant k is cut into lengths of ratio 1 2 3 They are connected in series and the new force constant is k Then they are connected in parallel and force constant is K Then K K is NEET 2017 1 1 6 2 1 9 3 1 11 4 1 14

Three equal negative charges of magnitude 9 each are at the vertices of an equilateral triangle of side d How much work will have to be done by an external agency to arrange the charges into a configuration in which the three charges are at the vertices of an equilateral triangle of side 2d A B C D 3q 8 d A 3q 8 d 6q 4 d 6q

A particle is projected from horizontal ground at some angle such that its horizontal component is ux and vertical component is uy and luxl luyl 20 m s If maximum possible range of particle is 5x meter then x is Ux

4 t and t 3 t and t Which of the following velocity time graphs 12 shows a realistic situation for a body in motion 12 I 3 1 1 4 1 fatter and arafas fafal 12 L 3 1 2 9 IN 0

A swimmer can swim in still water at a ran If he swims in a river flowing at 3 0 km h and keeps hi direction with respect to water perpendicular to the current find his velocity with respect to the ground 41

charge Q is of opposite polarity to that of q 8 When no current passes through a conductor choose which one of the following is incorrect 1 The average velocity of a free electrons over a large period of time is zero 2 The average of the velocities of all the free electrons at an instant is zero 3 The free electrons are randomly moving 4 The average speed of a free electron over a

The graph shown below shows variation of de Broglie wavelength A versus where Vis accelerating potential for three charged particles of equal charges but different masses B A OMA MB Mc OmB mc MA OMA MC MB OMB MA Mc V

I think the correct answer should be 4th option but the b ook says 2nd Please tell me if I am wrong and please expl ain the question properly to me if I am wrong 3 1 7 4 8 4 1 2 4 8 4 8 4 1 A 8 4 units CE B 1 unit D represented by CE on the given number line 24 Which of the following irrational numbers is

View In English An apparatus is connected to an ideal battery as shown in figure For what value of current power delivered to the apparatus will be maximum apparatus 42 Correct Answer 2 Your Answer 1 Status incorrect E RE 2R E 4R information is insufficient Add to Bookmark List A magnet oscillating with rate of 50 jew iew

The variables x and y are related by the equation Sy 2 x 20 where h is a constant Diagram 5 shows the straight line MN obtained by plotting xy against x 0 NO Diagram 5 20 a Express the equation Sy 2 x in linear form which is used to obtain the straight X hown in Diagram 5

A B Two conducting rings A and B are placed in a time varying magnetic field Both are made of identica wires and the radius of A is twice that of B TH induced current in A is 1 equal to that in B 3 half that in B 2 4 twice that in B four times that in

2 7 Figure shows a small wheel fixed coaxially on a bigger one of double the radius The system rotates about the common axis The strings supporting A and B do not slip on the wheels If x and y be the distances travelled by A and B in the same time interval then 1 x 2y A B 2 x y

It will rer Suppose the Saturn rings consist of football size particles orbiting in circular orbits If the maximum speed of these particles is 1 05 times of the minimum speed find ratio of radial width to the inner radius of the ring a 0 01 c 0 10 b 0 05 d 0 25

AB and CD are fixed conducting smooth rails placed in a vertical plane and joined by a constant current source at its upper end PQ is a conducting rod which is free to slide on the rails A horizontal uniform magnetic field exists in space as shown If the rod PQ is released from rest then A The rod PQ may move downward with constant acceleration 2 The rod PQ may move upward with constant acceleration 3 The rod will move downward with decreasing acceleration and finally aquire a constant velocity 4 either A or B plo

CP Electromagi Magnetic flux in weber linked with a closed circuit of resistance 10 ohm varies with time t in seconds as 6 5 4t 1 The induced electromotive force in the circut at t 0 2 sec is 1 0 4 volts 2 0 4 volts 3 2 0 volts 2 0 2 0 volts 07 tot 2 L

The waves of 600 m wave length are incident normally on a slit of 1 2mm width The value of diffraction angle corresponding to the first minima will be in radian 1 7 2 3 3 2 56 4

Three identical coils A B and C are placed coaxially with their planes parallel to each other The coil A and C carry equal currents in opposite direction as shown The coils B and C are fixed and the coil A is moved towards B with a uniform speed then B 000 A there will be induced current in coil B which will be opposite to the direction of current in A 2 there will be induced current in coil B in the same direction as in A 3 there will be no induced current in B 4 current induced by coils A and C in coil B will be equal and opposite therefore net current in B will be zero ronches to ring then direction of induced current in ring is

Energy is stored in the choke coil in the form of 1 Heat 3 Magnetic energy 2 Electric energy 4 Electro magnetic energy 004 H than work done by source to establish a current of 5A in it

OR Write the expression for speed of electromagnetic waves in a medium of electr permittivity and magnetic permeability u 22 An a particle and a proton are accelerated th

Q 2 A fixed long thin wire carrying current I lies along the x axis A fixed square loop of side length a is placed on the xy plane so that two of its sides are parallel to the x axis and the other two are parallel to the y axis The side parallel to and closest to the wire is at a distances from the wire The loop also carries a current I in the clockwise direction What is the total force on the loop due the wire Max score 1 Neg score 0 2 1 a Ts a s MoI a 2 s a s HoI a Ts a s HoI q a 4 s a s

The displacement of two identical particle executing SHM are represented by equ 8 sin 10t 6 and x 5 sin wt For what value of w energy of both the particle is same a 4 units b 8 units d 20 units c 16 units A CO

2 3 weber 0 5 weber B Bo p 0 02 cos 100nt weber turns and number of turns is 50 in the coil the maximum induced emf is 4 6 28 volt 2 0 weber 3 weber 2 314 volt 2 100 volt 3 31 4 volt netic flux linked with the coil varies with time as d 3t 4t 9 The magnitude of induced emfatt

The path of a projectile thrown vertically upwards is as as shown Select incorrect statement Question Type Single Correct Type 1 B C At D 2 time taken from A to B time taken from C to D time taken from A to C time taken from B to D

D 1 2 2 1 2 An ideal gas is compressed to half its initial volume by means of several processes Which of the process results in the maximum work done on the gas NEET 205 1 isochoric 2 isothermal 3 adiabatic isobaric works between 4 C and 30 C It is required to remove 600 calories of heat every second in order to 120

Two distant stars X and Y are observed in the sky Star X emits blue light whereas Star Y emits red light Which of the following conclusions can you draw from the above observation ans Star X is brighter than Star Y Star X is younger than Star Y Star X is older than Star Y Star X is cooler that Star Y

1 30 k Assertion In adiabatic process change in internal energy is equal to work done on gas Reason In adiabatic process no heat exchange with surrounding 1 If both Assertion Reason are true the Reason is a correct explanation of the Assertion 2 If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion 3 If Assertion is true but the Reason is false 4 If Assertion Reason both are false AIIMS 2018 If is given of the gas what is change in

Very Short Answer Type Questions 1 According to the New Cartesian Sign Convention for mirrors what sign has been given to the focal leng of 1 a concave mirror ii a convex mirror 2 Which type of mirror has a positive focal length b negative focal length 3 What is the nature of a mirror having a focal length of 10 cm 4 What kind of mirror can have a focal length of 20 cm 5 Complete the following sentence All the distances are measured from the of a spherical mirror 6 What sign ve or ve has been given to the following on the basis of Cartesian Sign Convention a Height of a real image b Height of a virtual image

The torque on a bar magnet due to the earth s magnetic field is maximum when the axis of the magnet is O Perpendicular to the field of the earth O Parallel to the vertical component of the earth s field A an angle of 33 with respect to the N S direction Along the North South N S direction

A particle is confined to move along x axis has a wave function y Cx between x 0 and x 1 0 v 0 elsewhere The value of the constant C is ans 31 2 3 1 2 1 12

A body of mass m was slowly pulled up the hill by a force F which at each point was directed along the tangent of the trajectory All surfaces are smooth Find the work performed by this force m h

What should be the pressure inside a small ait bubble of 0 1 mm radius situated just below the water surface Surface tension of water 7 2 10 N m and atmospheric pressure 1 013 105 N m 1 2 012 105 N m 2 2 012 104 N m 3 1 027 105 N m 4 1 027 104 N m

2R he two ends of a uniform thin rod of length and of mass 2 kg can move without friction along a fixed vertical circular path of radius R The rod is released fr e vertical position ab Find the force in N exerted by an end of the rod on the path when the rod passes the horizontal position cd

Fig shows a horizontal solenoid connected to a battery and a switch A copper ring is placed on a frictionless track the axis of the ring being along the axis of the solenoid As the switch is closed the ring will T remain stationary 3 move away from the solenoid 100000 HE Ack 2 move towards the solenoid 4 move towards the solenoid or away from it depending on connected to the left end of the solenoid

2 less than g Two identical coils A and B are arranged coaxially as shown in the figure and the sign convention adopted is that the direction of currents are taken as positive when they flow in the direction of arrows Which of the following statements is correct 00 1 If A carries a steady positive current and A is moved towards B than a positive current is induced in B 2 If A carries a steady positive current and B is moved towards A then a negative current is induced in B 3 If both coils carry positive current then the coils repel each other 4 If a positive current flowing in A is switched off then a negative current is induced momentarily in B orallel to each other The coil A and C carry equ

Example 65 Round off the following numbers as indicated 1 18 35 upto 3 digits iii 18967 upto 3 digits v 248337 upto 3 digits vii 101 55 x 106 upto 4 digits ii 31 325x 105 upto 4 digits ii 143 45 upto 4 digits iv 12 653 upto 3 digits vi 321 135 upto 5 digits

Q 53 Heat produced in a current carrying conducting wire is H I Rt it percentage error in I R and t is 2 4 and 2 respectively then total percentage error in measurement of heat energy a 8 b 15 c 5 d 10 Q 54 The resistance of two resistance wires are R 100 5 2 and R 200 7 are connected in series Find the percentage error in the equivalent resistance of the combination a 8 5 b 12 c 4 d 9

Consider a uniform spherical charge distribution of radius R centred at the origin O In this distribution a spherical cavity of radius R2 centred at P with distance OP a R R see figure is made If the electric field inside the cavity at position is E F then the correct Ri statement s is are A E is uniform its magnitude is independent of R but its direction depends on r B E is uniform its magnitude depends on R and its direction depends on C E is uniform its magnitude is independent of a but its direction depends on a D E is uniform and both its magnitude and direction depend on a

An intense light source radiate uniformly in all directions At a distance of 5 0 m from the source the radiation pressure on the perfectly absorbing surface is 9 0 x 10 6 Pa What is total average power output of the source Question Type Single Correct Type 1 649 KW

21 A particle of charge q is moving with velocity v in the presence of crossed electric field E and magnetic field B as shown in the figure i Write an expression for the force experienced by the charge and under what condition will the particle to move along the x axis ii How the trajectory of the particle would be affected if the electric field is switched off and the velocity has a component along B Draw it FE E V

c 3 Volt d 4 2 Volt 35 A current of 6A enters one corner P of an equilateral triangle PQR having 3 wires of resistances 20 each and leaves by the corner R Then the current I and 1 are KCET 2006 6A a 244A b 4A2A c 14 2A d 24 3A Q 292 A current 2 A flows through a 202 resistor when connected across a battery The same battery supplies a current 05 A 292 I WWW P 12 WW 202 R 41 a 2 A c 1 A A battery resistance current I R alone best desc a I ap b I ap c I ap

experiment the slit separation d is 0 3 mm and the screen distance D is 1 m A parallel beam of light of wavelength 600 nm is incident on the slits at angle a as shown in figure On the screen the point O is equidistant from the slits and distance PO Which of the following statements s is are correct is 11 0 mm 0 36 D A For TC B Fringe spacing depends on 0 36 C For a Screen y P degree there will be destructive interference at point O TC D For a 0 there will be constructive interference at point P 0 degree there will be destructive interference at point P 201

momentum of the system If one object within the system loses momentum it is gained by the other object within the system The combined momentum of both objects would be conserved Getting Ready Navigate to the Collision Carts Interactive in the Physics Interactives section of The Physics Classroom website http www physicsclassroom com Physics Interactives Momentum and Collisions Collision Carts physicsclassroom com Physics Interactives Momentum and Collisions Collision Carts Once the Interactive opens resize it as desired Select the Elastic Collisions option Experiment with changing the Mass and the Initial Velocity of the two carts Observe how the position of the carts along the track can be changed by dragging Learn to Start Pause and Reset the animation Path Collision 1 Blue Cart Initially at Rest Set the initial blue cart velocity to 0 m s Set the mass values to different values Run the simulation and record the mass and velocity values Before Collision Red Cart Blue Cart m s mRed Vred kg x kg Use mass and velocity values to complete the following momentum table Before Collision After Collision kg x kg x m s kg m s m s After Collision kg m s m s malec Valur kg x m s kg m s m s kg m s kg m s AMomentum

A uniform rod AB of length L 2 3 m and weight W 124 N acting through the centre of the rod is supported by two vertical strings at its ends Suspended from the rod at a distance of x 0 77 m from A is a load of m 21 kg as shown in the diagram below Determine the tension in the string connected at B A m L W B Take the acceleration due to gravity as a 9 8