Physics Questions

A particle starts moving with velocity v 1 m s and acceleration a 1 m s radius of curvature of the particle at t 1 sec A 5 m C 675 m String B 5 5 m none m s2 Find the

S a 6 23 A particle having charge q enters a region of uniform magnetic field B directed inwards and is deflected as shown The magnitude of the momentum of the particle is qBy 2 qBy 2 a 0 2 X X y b 9By X d 9By2 2x BA

0 4 1 8 10 H A conducting rod AC of length 41 is rotated about 40 a point O in a uniform magnetic field B directed into the paper AO 1 and OC 31 Then X X X X X X X 1 VA Vo X Bol 2 X 7 2 Vo Vc Bol 3 VA Ve 4Bol 4 Ve Vo Bol o Bo 0 X C X 4 1 8 x 102 H X X X 1 V V un Bol 2 2 Vo Vc Bol 3 VA V 4Bol 4 Vc Vo Bol AC gi A131 X 0 X

1 3 75 10 N 2 3 75 10 N x 3 3 75 10 N 4 3 75 10 N 5 A metallic ring connected to a rod oscillates 35 freely like a pendulum If now a magnetic field is applied that the pendulum now swings through the fields The pendulum will 1 Keep oscillating with the old time period 2 Keep oscillating with a smaller time period 3 Keep oscillating with a larger time period 4 Come to rest very soon 1 3 75 10 N 3 3 75 10 N f 2 3 75 10 2N 4 3 75 x 10 N get ya uredia de af grafta de men and anfer en la at sa 1 2 enero 3 dich tet gi en he i afua g 4 f fear an

Two short magnets of equal dipote moments M are fastened perpendicularly at their centres as given in the figure The magnitude of the magnetic field at a distance d from the centre on the bisector of the right angle is Ho M a Ho 4n d NC c H 2 2M 4 d 9 P N S b Ho S 2 M 4 d AIIMS 2016 d Ho 2M 4 d

16 Two wires AO and OC carry equal currents i as shown in figure One end of both the wire extends to infinity Angle AOC is a The magnitude of magnetic field at a point P on the bisector of these two wires at a distance r from point O is a oot Hoi 2 r c HQ 1 cos2 2Tr a A P C b Ho i 4 r cot 9 Ho d sin 4 r 2

uniform 42 In a certain region of space there exists a constant and magnetic field of induction B The width of the magnetic field is a A charged particle having charge q is projected perpendicular to B and along the width of the field If deflection produced by the field perpendicular to the width is d then the magnitude of the momentum of the particle is af 2 a c d 2d 4d a d qB qB b X X X 92 202 98 d a d 2d X xx X qB X a d

4 A soap film of RI 1 33 and thickness t is illuminated by light of wavelength lamda incident at an angle 60deg The minimum thickness to observe the dark band at viewing angle 60deg for wavelength lamda is 3 Points lamda 5 x 10 5 cm 2 5 x10 5 cm 2 5x10 7 cm O 0 25micron

parabola 25 A conducting wire bent in the form of a y 2x carries a current i 2A as shown in figure This wire is placed in a uniform magnetic field B 4k tesla The magnetic force on the wire is in newton 16i y m 321 A 12 0 B x m c 32i d 16

A square of side L 2 is removed from one corner of a square sandwich that has sides of lengt L The center of mass of the remainder of the sandwich moves from C to C The displacemen 2 of the x coordinate of the center of mass from C to C is p L The value of p is 12

ALLEN 13 For angles of projection of a projectile 45 0 and 45 0 the horizontal ranges described by the projectile are in the ratio of if 0 45 1 2 1 2 1 2 3 1 1 4 2 3 45 0 45 ca a af 0 45 1 2 1 3 1 1 8 fa 2 1 2 0

Unit vector along a ray of light that is incident on a plane mirror is 3 k and unit vector along the normal to the mirror at the point incidence is 3 unit vector along the reflected ray can be expressed as

Block A is placed on the horizontal surface while block B is on the inclined one The blocks are connected by a cord and coefficient of friction are indicated in the figure Solve for the magnitude and direction of force P which will cause impending motion Als find the tension if the cord attached to the blocks P 200 200N A f 0 2 450 f 0 3 200N B 300

A particle in a certain conservative force field ha 2x y z a potential energy given by U exerted on it is 1 2 4xy i x i x v k 2 2 3 2x 2 2 42 k 4 4xy 4x y Z 3 2 3 4xy i x 4x y k 2 3 Z 4xy 2x 4x y The force

36 An a particle is moving along a circle of radius R with a constant angular velocity w Point A lies in the same plane at a distance 2R from the centre Point A records magnetic field produced by the a particle If the minimum time interval between two successive times at which A records zero magnetic field is t the angular speed w in terms of t is 2 2 a c t TC 3t b d 3t TC 2t

nal area h 10 cm eased to modulus locity of section cm and p filled Own in 20 is scible econd mental Q 29 A thermometer has a spherical bulb of volume 1 cm having 1 cm of mercury A long cylindrical capillary tube is connected to spherical bulb Volumetric coefficient of expansion of mercury is 1 8 x 10 K cross section area of capillary is 1 8 10 cm Ignoring expansion of glass cm far apart on the stem are marks indicating 1K temperature change mmmmmmm tutwulwinul

Least count LC is the minimum length measured by a Vernier callipers and Let us define Vernier constant VC 1 MSD 1 VSD Each main Scale division MSD of the callipers is 1mm and N divisions of main scale are divided into 10 Vernier scale divisions VSD If N 6 find LC in mm

14 Figure gives a system of logic gates From the study of truth table it can be found that to produce a high output 1 at R we must have X Y A X 0 Y 1 C X 1 Y 0 P O R B X 1 Y 1 D X 0 Y 0

4 It is equal to the mass of 1 mol of element in amu If the atomic mass unit u were defined to be 50 one fifth of the mass of C 12 what would be the atomic weight of N in amu on new scale 1 33 6 2 5 83 3 11 67 4 2 80 4 afe 441 41 3 1 1 5 1 33 6 3 11 67 4 12 g Namu 2 5 83 4 2 80

3 k and unit vector along the normal to t Unit vector along a ray of light that is incident on a plane mirror is 3 unit vector along the reflected ray can be expressed as mirror at the point incidence is

33 A string fixed at both ends is vibrating in the lowest mode of vibration for which a point at quarter of its length from one end is a point of maximum displacement The frequency of vibration in this mode is 100 Hz What will be the frequency emitted when it vibrates in the next mode such that this point is again a point of maximum displacement a 400 Hz c 600 Hz b 200 Hz d 300 Hz

3 89 At the time of total solar eclipse the spectrum of sol radiation will have MHT CE a a large number of dark Fraunhofer lines b a smaller number of dark Fraunhofer lines c po lines at all at 8 de Fraunhofer lines changed into bright coloured li

ABCD is a square where each side is uniform wire of resistance 12 Find a point E on CD such that if a uniform wire of resistance 12 is connected across AE and a constant potential difference is applied across A and C the points B and E will be equipotential

kg and amplitude A 2m the variation of potential energy U as function of displacement x from mean position is as shown The time period of oscillation in seconds is 1 T 3 RIN 2 2m UA 30 J TO J 0 2m 2 2 4 4 X

L Vgen i R M HE The circuit shown above has R 6 Ohms L 1 H and C 40 mF The capacitor has the initial voltage of Vc 0 4 00 volts and the switch is closed at t 0 The source voltage is Vgen 40t We want to write the IVP for this circuit Write the value of i 0

Which of the following statements is false The energy spectrum of a decay is line spectrum The energy spectrum of B particles is continuous The energy spectrum of y decay is continuous The energy spectra of a y decay are line spectra

ARGER ENDEAVOUR A photo conductive cell 1 1mm CdS crystal is illuminated with light of wavelength 450 nm and intensity 1 mw cm Assuming quantum efficiency of unity Calculate the number of electron hole pairs generated per second given the energy band gap of CdS is 2 6 eV

Which of the following statement is incorrect about photo electric effect It is based on particle nature of light Stopping potential depends on the intensity of incident light having fixed frequency Saturation current depends on the intensity of incident light having fixed frequency Frequency should be greater than threshold frequency for emission of electrons

1 2 1 15 16 3 1 m s 3 m s H 4 5 in metres 6 2 7 Above diagram represents a multiflash photograph of an object P moving along a horizontal surface The successive positions as indicated in the diagram are separated by equal time intervals of 1 second The first flash occurred just as the object started to move and the last just as it came to rest The average speed of the object during the motion is 8 16 15 4 0 9 m s 9 m s 10 X2 1202 619 2

The mass difference between the pair of mirror nuclei C and B is given to be AMeV c According 6 17 17 9 to the semi empirical mass formula the mass difference between the pair of mirror nuclei F and O will approximately be rest mass of proton m 938 27 MeV c and rest mass of neutron m 939 57 MeV c n a 1 39 AMeV c b 30V 50 5 MeV c C AMCV d 1 6 A 0 78 MeV c LOC WEY

34 The horizontal range and the maximum height of a projectile are equal The angle of projection of the projectiles is 4 c 0 tan 2 a 0 tan by0 tan 4 d 0 45 AIPMT Pre 12

In the following four situations charged particles are at equal distance from the argin Arrange them according to the magnitude of the net electric field at origin greatest first ii A iii 5q O i ii iii iv B ii i iii iv C i iii ii iv 34 iv O the O

Young s double slit experiment is performed in air central maxima is obtained on screen at some position Two slabs are placed in front of two slits S and S The slab placed in front of S is of thickness t and of refractive index 1 6 and the slab placed in front of S is of refractive index 1 4 Find its thickness if position of central maxima remain unchanged on putting two slabs 1 1 5 t 2 1 4 t 3 1 6 t 4 S

Water is filled in a container upto height of 3m A small hole of area Ao is punched in the wall of the container at a height 52 5 cm from the bottom The cross sectional area of the container is A If Ao A 0 1 then 1 is where v is the velocity of water coming out of the hole A 50 m s B 50 5 m s C 51 m s D 52 m s A A You Missed

01 Two coils A and B have coefficient of mutual inductance M 2H The magnetic flux pass ing through coil A change by 4 Weber in 10 seconds due to the change in current in B Then A change in current in B in this time inter val is 0 5 A B the change in current in B in this time interval is 2A C the change in current in B in this time interval is 8 A D a change in current of 1 A in coil A will produce a change in flux passing through B by 4 Weber 1

Two coherent sources are 0 3 mm apart They are 1 m away from the screen The second dark fringe is at a distance of 0 3 cm from the centre Distance of fourth bright fringe from the centre is Only one correct answer A 0 6 cm B C 0 8 cm 1 2 CM i

38 In Fresnel diffraction if the distance between the disc and the screen is decreased the intensity of central bright spot will a biqu a Increase b Decrease igi c Remain constant fide d None of these d

35 A certain body weighs 22 42 g and has a measured volume of 4 7 cc The possible errors in the measurement of mass and volume are 0 01 g and 0 1 cc Then maximum error in the density will be 2 d 0 02 22 c 0 2 CBSE PMT 91

A 200 kg satellite is revolving around earth in circular orbit of radius 2R Amount of energy required to transfer it to a circular orbit of radius 4R is M 6 1024 kg R 6 4 106 m O 1 57 10 J 1 57 x 106 J 3 13 x 10 J 12 106 1

laced with time 300 rad ngle of 60 mf is magnetic en the em c field is are the 1 Mon n r l 2 M M M r l 3 Mo M M 52 l rcular col 4 Mon n ry l CO wo coils A and B having turns 300 and 600 respectively are placed near each other On passing a current of 3A in A the flux linked with A is 1 2 x 10 4 Wb and with B it is 9 x 10 5 Wb The mutual inductance is 1 4 x 10 5 H 2 3 10 5 H 3 2 10 5 H 4 1 8 x 10 2 H 19 The primary and secondary coils of a transformer have 60 and 1800 turns respectively If the ntic flux linked with the primary coil is given o is constant the output mil is where and field is moved R The emf is in plate due place here A When decres emf R TE A

11 A rigid circular loop of radius r and mass m lies in the x y plane on a flat table and has a current i flowing in it At this particular place the earth s magnetic field is B Bxi B k The value of i so that one edge of the loop lifts from the table is a c mg B B mg TrBx b d mg rBz mg Tr BB

Find the flux passing through the shaded rectangular plane which passes through the axis due to the long straight current carrying conductor having a current i Given length 1m current I 2A Radius in weber Write value of n R 5cm If answer is n Hol 1 16 R

A charge in motion can exert force on a statinary bar mag net Conversely a bar magnet in motion can lead to a ford e on stationary charges 7 A charge in motion can exert force on a stationary magnet Conversely a bar magnet in motion can lead to a force on stationary charges This statement is NCERT Pg 213

city 4 Thrust wance The period of oscillation of a simple pendulum in in rock an experiment is recorded as 2 63s 2 56s 2 42s 2 71s and 2 80s respectively The average absolute error is 1 0 1s The length breadth and thickm 2 0 11s 3 0 01s 4 1 0s

ALLEN 5 A flux of Im Wb passes through a strip having 25 an area A 0 02 m The plane of the strip is at an angle of 60 to the direction of a uniform field B The value of B is 1 0 1 T 3 4 0 mT 2 0 058T 4 None of the above A 0 02 m f1 m Wb faa y un graf a af Bfm 60 m 1 0 1 T 3 4 0 mT 2 0 058T 4 3

The magnetic field at the centre of a circular current carrying loop of radius Ris B The magnetic field on its axis at a distance R from the centre is B The value of B B will be O 2 1 01 2 O 2 2 1

X axis Two wires of same length are shaped into a square and a circle If they carry same current ratio of the magnetic moment is MINI 1 2 n 2 x 2 3 4 4 4 T NTHUSE LEADER ACHIEVER ALPHA PLUS SPARK GRAS 14082021

An object is placed on the principal axis of a concave mirror of focal length 10 cm at a distance 8 0 cm from the pole The image is formed at a distance of Nx10 cm from the pole of mirror determine N Write an answer

Two coherent light sources P and Q are at a distance 3A from each other as shown in the figure The distance from Pon the x axis at which constructive interference may take place is y axis 3 2 4 3 4 x axis

Real and inverted image of an object is formed at a distance d 40 cm from the object The size of the image is half of that of object List 1 d 1 The nature of lens used should be 2 Focal length of the lens 3 Distance of object from the lens 4 If mirror were used then nature of mirror should be List 2 A Concave B Convex C 80 3 cm D 80 9 cm