Physics Questions

Consider the conservation of energy equation below AK AU AE int W Q TMW TMT TET TER A ball of mass m falls from a height h to the floor a Identify the appropriate version of the equation above for the system of the ball and the Earth O AEint Q TET TER O AU W OAK W OAK AU 0 Use this equation to calculate the speed of the ball just before it strikes the Earth Use the following as necessary m for mass h for height g for acceleration due to gravity V b Identify the appropriate version of the equation above for the system of the ball O AK W O AEint Q TET TER OAK AU 0 O AU W Use this equation to calculate the speed of the ball just before it strikes the Earth Use the following as necessary m for mass h for height g for acceleration due to gravity

on ng 29 The solubility of a specific non volatile salt is high at 25 C If 2gm 4gm and 6gm of the salt added to 100gm at 25 C the vapour pressure X Y Z respectively will follow the order of 1 X Y Z 2 X Y Z 3 Z Y X 4 X Y Z in water at 25 C is 2 105

4 If Assertion Reason both are false Two chambers containing m g and m g of a gas at pressure P and P respectively are put in communication with each other temperature remaining constant The common pressure reached will be AIIMS 2017 PP m m 1 P m P m 2 PP m P m P m m m P P P m Pm 4 m m P P m Pm constant pressure the fraction of the heat energy supplied which increases 3

An ideal gas is initially at temperature T and volume V Its volume is increased by AV due to an increase temperature AT pressure remaining constant The quantity 8 AV varies with temperature as VAT 1 T AT 2 THAT Tamn K T AT Temn k T AT

molecule of the gas is m Which of the following gives the density 3 P KTV 1 P KT 2 Pm KT 4 mkT The temperature inside a refrigerator is t C and the room temperature is t C The amount of heat delivered to the room for each joule of electrical energy consumed ideally will be NEET II 2016 1 4 273 1 1 4 1 1 1 273 2 3 L 273 4 4 1 t NEET II 2016 l of an ideal monoatomic gas undergoes a process described by the equation PV constant The heat

If identical charges q are placed at each corner of a cube of side b then electric potential energy of charge q which is placed at centre of the cube will be 1 2 8 2q 4 eob 3 8 2q TEOb 4 2q TEOb 40

The number of photons from a light of wavelength 5000 required to do one joule of work is a 1 25 x 1020 m b 1 5 x 1020 m c 2 25 x 1020 m d 2 5 x 1020 m U

33 If a steady current I is flowing element ABC Choose the correct relationship 2r B 1 2 7 1 2 C a VAB 2VBC b Power across BC is 4 times the power across AB c Current densities in AB and BC are equal d Electric field due to current inside AB and BC are

A solid dielectric material has 4 x 1028 atoms per unit volume if it shows an electronic polarizability of 1 5 x 10 40 Fm then the dielectric constant of the material is ans 1 0 1 88 1 2 4 3

31 The magnetic flux near the axis and inside the a core solenoid of length 60 cm carrying current I 1 57 x 10 Wb Its magnetic moment will cross sectional area of a solenoid is very small compared to its length o 4 x 107 SI unit a 0 25 A b 0 50 A c 0 75 A d 1 A MHT CF

A stretched wire emits a fundamental note of 256 Hz Keeping the stretching force constant and reducing the length of wire by 10 cm the fundamental frequency becomes 320 Hz the original length of the wire is Question Type Single Correct Type 1 100 cm 2 50 cm 3 400 cm 200 cm

A particle under the action of a SHM has a period of 3 s and under the effect of another it has a period 4 s What will be its period under the combined action of both the SHM s in the same direction a 7 s c 2 4 s b 5 s d 0 4 s

In a coil of resistance 102 the induced current developed by changing magnetic flux through it is shown in figure as a function of time The magnitude of change in flux through the coil in Weber is i amp O 216 0 1 t s 4 4 AIPMT 2012

A conducting ring lies fixed on a horizontal plane If a charged nonmagnetic particle is released from a point on the axis at some height from the plane then 1 an induced current will flow in clockwise or anticlockwise direction in the loop depending upon the nature of the charge 2 the acceleration of the particle will decrease as it comes down 3 the rate of production of heat in the ring will increase as the particle comes down 4 no heat will be produced in the ring

4 If Assertion Reason both are false A closed vessel explodes at 15 atm pressure If temperature of the vessel is 300 K at 10 atm pressure then find at w temperature will vessel explodes AIIMS 201 1 250 K 2 420 K 4 450 K 3 200 K

The flow speeds of air on the lower and upper surfaces of the wing of an aeroplane are v and 2 v respectively The density of air is p and surface area of wing is A The dynamic lift on the wing is Question Type Single Correct Type 1 pv A 2 2 pv A

P m P m P m P m P m P m When an ideal monoatomic gas is heated at constant pressure the fraction of the heat energy supplied which increases the internal energy of the gas is AIIMS 2017 1 2 5 12 3 5 3 3 7 4 5 7 carnot engine operates with source at 127 C If the source supplies 40 kJ of heat energy the work done by the JAIIMS 2017

3 4 C 17 Consider the combination of resistors as shown in figure and pick out the correct statement R wwww R A www R6 wwwwww R R www www R5 1 R R are connected in parallel 2 R R are connected in series 3 R R are connected in parallel B

The temperature entropy diagram of a reversible engine cycle is given in the figure Its efficiency is AIEEE 2005 2T S 2S S 4 2 N

The following questions consist of two statements each printed as Assertion and Reason While answering these questions you are required to choose any one of the following responses 11 A If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion B If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion C If Assertion is true but the Reason is false D If both Assertion and Reason are false Assertion Ampere s law is to Biot Savart law what Gauss s law is to Coulomb s law Reason Both Ampere s and Gauss s law relate a physical quantity on the periphery or boundary magnetic or electric field to another physical quantity namely the source in the interior current or charge We also note that Ampere s circuital law holds for steady currents which do not fluctuate with time a A b B c C d D

The half life of a radioactive isotope X is 25 years It decays to another element Y which is stable The two elements X and Y were found to be in the ratio of 1 15 in a sample of a given rock The age of the rock was estimated to be Question Type Single Correct Type 1 150 years 2 200 years 3 250 years 4 100 years

The volume V of a monoatomic gas varies with its temperature T as shown in the graph The ratio of work done by the gas to the heat absorbed by it when it undergoes a change from state A to state B is NEET 2018 410215 2 2 3 3 1 3 vd T 4 2 7 1 013 x 105 Nm2 requires 54 cal of heat energy to

A vibrator of mass 1 g is acted upon by a restoring force of 104 N m of displacement a retarding force of 4 Ns m and a driving force o cos Wt N The maximum possible amplitude is Select one a 1 02 X 10 1 m b 1 X 10 m c 2 02 X 10 1 d 2 x 103 m

A magnet of magnetic moment 2JT 1 is aligned in the direction of magnetic field of 0 1 T What is the net work done to bring the magnet normal to the magnetic field 0 0 1 J 0 0 2 J 01J

c 1 m s A body of mass m 3 513 kg is moving along the x axis with a speed of 5 00 ms The magnitude of its momentum is recorded as AIEEE 2008 a 17 565 kg ms 1 c 17 57 kg ms b 17 56 kg ms d 17 6 kg ms

1 C 3 C 5 2 C 4 C 6 3 C 3 C 2 Hydrogen gas is filled in a container of volume 20 litre Average translational kinetic energy of all its molecules is 1 5 x 105 J Pressure of hydrogen in cylinder is RPMT 2010 1 2 x 106 N m 2 3 x 106 N m 3 4 x 106 N m 4 5 x 106 N m 100gica at 0 C is put in water in bucket at 50 C On complete melting change in entropy will be Assuming no change IRPMT 20101

A three level laser emits a light of wavelength 4500 The temperature at which the ratio of the population reduces to half is a 46244 K b 37800 K c 32000 K d 84872 K Hint h 6 63 x 10 34 Joule sec k 1 38 x 10 23 Joule kelvin

In Young s experiment the ratio of maximum to minimum intensities of the fringe system is 4 1 The amplitudes of the coherent sources are in the ratio RPMT 1996 MP PET 2000 RPET 2001 MP PMT 2001 b 3 1 d 1 1 a 4 1 c 2 1

1 To determine the coefficient of friction between a rough surface and a block the surface is kept inclined at 45 and the block is released from rest The block takes a time t in moving a distance d The rough surface is then replaced by a smooth surface and the same experiment is repeated The block now takes a time t 2 in moving down the same distance d The coefficient of friction is WB JEE 2014

9 is projected horizontally from top of a tower If v is the velocity at any instant and radius of curvature of the path of the particle at that instant is directly proportional to v then find the value of n 8 P is a movable point moving with constant speed 20 m s such that its velocity vector always maintains an angle 37 with line OP If initial distance between O and P is 80 m After what time in s shall P reach O ST 20 m s EDMI NOTE 8 QUAD CAMERA 80 On a frictionless horizontal surface x y plane a small trolley A is moving along a straight line parallel to y axis with constant speed of 3 1 m s A ball is thrown along the surface from the origin O when trolley was at A Its velocity makes an angle with the x axis and it hits the trolley If e is the angle made by the velocity vector of the ball with x axis in the frame of trolley find the speed in m s of the ball with respect to the surface 40 where 3 3 1 m s AU

2 A block of mass M sits on an inclined plane and is connected via a massless string through a massless pulley A that slides without friction on the plane to a fixed post This pulley is in turn connected via a massless string through a second massless pulley B to a second block of mass 2M that hangs above the ground The coefficient of static friction between the inclined plane and block resting on the inclined plane is The inclined plane is tilted to an angle 0 w r t horizontal so the blocks just start to move Find the value of the quantity 3 cos 0 sin 0 2M 0

A firefighter a distance d 10 0 m from a burning building directs a a stream of water from a fire hose at angle 0 60 If the initial spe of the stream is t 20 m s At what height h does the water strike the building

Potential energy sinusoidal curve is shown graphically for a particle The potential energy does not depend on y and z co ordinates For range 0 x 2 maximum value of conservative force in magnitude is B Find the value of Here this force is corresponding to above potential energy and all units are in SI 6 3 0 U Joule B 1 2 1 3 2 2 x metre

In Young s double slit experiment the distance between slits and the screen is 1 0 m and monochromatic light of 600 nm is being used A person standing near the slits is looking at the fringe pattern When the separation between the slits is varied the interference pattern disappears for a particular distance de between the slits If the angular resolution of 1 the eye is the value of d is close to 60 a Imm h 3mm c 2mm d 4mm

A conductor in the shape of a square loop of edge length 0 400 m carries a current I 10 A as in the figure Calculate the magnitude and direction of the magnetic field at the center of the square e

An electron and a proton enter region of uniform magnetic field in a direction at right angles to the field with the same kinetic energy They describe circular paths of radius re and Tp respectively Then Question Type Single Correct Type 1 Tep 2 Tep 3 In

In damped oscillations the amplitude after 50 oscillations is 0 8 ao where ao is the initial amplitude then the amplitude after 150 oscillations is Question Type Single Correct Type 1 0 512 ao 2 0 280 aa

Two identical photocathode receive light of frequencies f and f2 If the velocities of the photoelectrons of mass m coming out are respectively v and v then Question Type Single Correct Type 1 v v2 2 V V 3 2h f f 2h f f2 12 f f 2h 12h 1 2 11 2

A particle of mass m confined between 0 x l has a probability 64 of occupying the ground state and a probability 36 of occupying the first excited state The average energy of the particle is Select one a 1 04 n ml b 0 36 2mL c 0 64 n mL2 d 1 04 n ml

A whistle emitting a sound of frequency 450 Hz approaches a stationary observer at a speed of 33 m s Velocity of sound is 330 m s The frequency heard by the observer in Hz is 409 429 hr mi 517

In the arrangement shown in figure coefficient of friction between the two blocks is 2 force of friction acting between the two blocks is g 10 ms F 20N 2kg 4 kg F 2N smooth DY AN

What is the relation between temperature of a body and the wavelength of its emitted radiation at its maximum emissive power Select one a none b as temperature of a body increases the wavelength of its emitted radiation decreases at its maximum emissive power c as temperature of a body increases the wavelength of its emitted radiation also increases at its maximum emissive power d as temperature of a body increases the wavelength of its emitted radiation does not change only at its maximum emissive power

An oil drop of mass 50 mg and of charge 5 C is just balanced in air against the force of gravity Calculate the strength of the electric field required to balance it g 9 8 ms 2 a 98 NC upwards b 98 NC downwards c 9 8 NC towards north d 9 8 NC towards south

The engine of a train passes an electric pole with a velocity u and the last compartment of the train crosses the same pole with a velocity v Then find the velocity with which the mid point of the train passes the pole Question Type Single Correct Type 1 2 3 u v 2 U V 2 u v 2

Focal length of an equiconvex lens is 20 cm The refractive index of material of the lens is 1 5 Now one of the curved surface is silvered At what distance from the lens an object is to be placed so that image coincides with the object

Two short magnets placed along the same axis with their like poles facing each other repel each other with a force which varies inversely as Square of the distance Cube of the distance Distance

3 A time varying magnetic field is present in a cylindrical region of radius R as shown in the figure A positive charge q is taken slowly from P to Q through POQ the magnetic field varies with time as B Bot where Bo is a constant and directed into the plane of the paper If W is the 0 workdone then W P 1 Zero A X XX XX X X X XXXXXX O X XXXX X XXXX 2 Bo

1 mole of H gas is contained in a box of volume V 1 00 m at T 300 K The gas is heated to a temperature of T 3000 K and the gas gets converted to a gas of hydrogen atoms The final pressure vould be considering all gases to be ideal AIIMS 2015 2 2 times the pressure initially 4 20 times the pressure initially of a gas in an adiabatic process is zero and in an isothermal process is infinite 1 same as the pressure initially 310 times the pressure initially T

A convex mirror forms the image of an object such that the distance between the object and image is 60 cm and the magnification produced is 1 4 The focal length of the mirror will be Question Type Single Correct Type 1 8 6 cm 2 6 2 cm 3 10 cm 4 16 cm

A particle of mass 1 kg executing simple harmonic motion of period 20 s crosses the mean position at t 0 with velocity cm s A the maximum acceleration of the particle is 10 cm s B when it is 4 cm from the mean position its velocity is 67 10 cm s C the kinetic energy of the particle when its displacement is 5 cm from the mean position is D its velocity at displacement 6 cm from the mean position is 87 10 cm s 3 8x106 J