Physics Questions

th 1 The mber of rate of coil is 2019 then the input voltage JEE Main 2019 and current in the primary coil are a 220 V and 10 A c 440 V and 20 A Two coils P and Q are separated by some distance When magnetic flux of b 440 V and 5 A d 220 V and 20 A a current of 3 A flows through coil P a through Which of the following a 9 00 c 00 A planar loop of wire Initially at t 0 the the magnetic field If it axis in its plane then t maximum and minimu a 2 5 s and 7 5 s c 5 0 s and 10 0 s 103Wb passes through Q No current is passed through Q When no current passes through P and a current of 2 A passed through Q the flux through P is JEE Main 2019 a 6 67x10 Wb b 6 67 10 Wb c 3 67 10 Wb d 3 67x10 Wb

linder is placed on a horizontal surface particle is projected with speed u and it ses the cylinder by just touching at two points as shown in figure Then the intial peed with which the mass projected 6 5xm s The value of x is 60 R 0 6m

D Two cells when connected in series are balanced on 8 m on a potentiometer If the polar one of the cell is reversed they balance on 2 m The ratio of emf s of the two cells is a 3 5 c 3 4 b 5 3 d 4 3

a X Jn Jn n n There are two long co axial solenoids of same length 1 The inner and outer coils have radii r and r2 and number of turns per unit length n and n respectively The rate of mutual inductance to the self inductance of the inner coil is JEE Main 2019 a 2 n2 r2 2 ni ri n Tot 1 d b 2 r1 n1 r2 n d n

a 1 0kg mass hangs attached to a spring of length 50 cm the spring stretches by 2 cm The mass is pulled down until the length of the spring becomes 60 cm What is the amount of elastic energy stored in the spring in this condition if g 10 m s 1 1 5 Joule 2 2 0 Joule 3 2 5 Joule 4 3 0 Joule A 10 kg block is pulled in the vertical plane along a frictionless surface in the form of an arc of a circle of radius 10 m The applied force is of 200 N as shown in figure If the block had started from rest at A the velocity at B would be

A convex lens forms the image of an object of same magnification when the object is placed at 10 cm and 20 cm from the lens The focal length of the lens is 1 5 cm 3 25 cm 2 15 cm 4 30 cm

Refer to the figure rectangle PQRS represents the cross section of a uniform magnetic field region of 0 2 T An electron is projected at a speed of V 2 0 x 10 m s into the region at an angle of 30 to the direction of the magnetic field The length of the magnetic region is 0 01 m Find the number of revolution made by the electron before it leaves the magnetic field region P B S O O O 0 01 m 28 16 32 R

Consider a conical pendulum with a bob of nass 80 kg and length of string 10 m that makes an angle of 5 degrees with the vertical Determine a the horizontal and vertical components of the force exerted by the string on the pendulum and b the radial cceleration of the bob Also can you please draw out the horizontal and vertical forces on the picture please it would help me better to see it

Two thin wires rings each having a radius R are placed at a distance d apart with their axes coinciding The charges on the two rings are q and q The potential difference between the centres of the two rings is 2005 1 QR 4d 3 zero 2 4 Q 1 2 ER Q 1 4 ER 1 R d 1 R d

A hollow sphere is performing pure rolling then 9 find acceleration of it s centre of mass F M 1 3 6F 5M 2F 3M R Rough 2 3F 5M Telegram ne questionga 4 None of these 1 1 a 6F SM 2F 3M Mtaala a M R Rough 2 F 3F SM 4 F

The threshold frequency for a photosensitive metal is 3 3 1014 Hz If light of frequency 8 2 1014 Hz is incident on this metal the cut off voltage for the photoelectric emission is nearly 1 5 V 3 21 AIPMT Mains 2011 2 1 V 4 21

For example if a body is having acceleration of 1 m s 2 it means that body is increasing it speed at the rate of 1m s similarly if a body is having momentum of 5 kg m s What does it mean kindly explain in easy and simple language I am trying to find out but it is not clear to m

A fix amount of nitrogen gas 1 mole is taken and is subjected to pressure and temperature variation The experiment is performed at high pressure as well as high temperatures The results obtained are shown in the figures The correct variation of PV RT with P will be exhibited by UPSEAT 2001 PV RT a 4 c 2 2 0 1 0 4 3 2 b 3 d 1 1 100 200 400 600 P

An object of mass M is gently placed on a horizontal conveyor belt which is moving with uniform velocity v as shown in the figure The coefficient of static friction is u the coefficient of kinetic friction is and the acceleration of gravity is g Initially the object slips for a while but finally moves without slipping together with the belt How far the conveyor belt moves while the object is slipping A g B 2 g C g poooo D 2 g

6 A circular arc of wire subtends an angle 2 at the centre If it carries a current i and its radius of curvature is R then the magnetic field at the centre of the arc is II 1

9192 mg A pendulum bob of mass 80 mg and carrying a charge of 2x 10 8 C is at rest in a horizontal uniform electric field of 20 000 V m Find the tension in the thread of the pendulum and the angle it makes with the vertical Take g 9 8 ms

a 1 5x103 V A 20 Henry inductor coil is connected to a 10 ohm resistance in series as shown in figure The time at which rate of dissipation of energy joule s heat across resistance equal to the rate at which magnetic energy is stored in the JEE Main 2019 inductor is E 2 In 2 c 2 In 2 a i 10 Q2 ww moooooo 20 H b In 2 d In 2 and IN 201 cross section arma A C

Phy Section This section contains 35 SINGLE CORRECT TYPE questions Each question has 4 choices 1 2 3 and 4 C When a potential difference Vis applied across a conductor of length the drift speed of electrons is Proportional to V Proportional to Independent of V Proportional to

UNIVERSAL BOOK DEPOT 1960 1248 Electromagnetic Induction Three solenoid coils of same dimension same number of turns and same number of layers of windings are taken Coil 1 with inductance L was wound using a Mn wire of resistance 11 02 m coil 2 with inductance L was wound using the similar wire but the direction of winding was reversed in each layer coil 3 with inductance L3 was wound using a superconducting wire The self inductance of VITEEE 2008 the coils L L2 L3 are b L L L3 0 d L L L3 a L L L3 1 mado a L L L 0

15 Calculate the weight of lime CaO that can be prepared by heating 200kg of limestone CaCO3 which is 95 pure a 88 4kg b 106 4kg c 65 7kg d 198 3kg 16 A sample of PCl3 contains 1 4 mole of the substance How many atoms are there in the sample a 5 6 x 1023 b 8 43 x 1023 c 3 37 x 1024 17 The incorrect statement for 14g CO is a It occupies 2 24L at STP b It corresponds to mole of CO d 2 40 x 1024

45 A plano convex lens when silvered on the plane side behaves like a concave mirror of focal length 30 cm However when silvered on the convex side it behaves like a concave mirror of focal length 10 cm Then the refractive index of the lens is 2 2 0 4 1 5 1 1 0 3 3 0 ah Work

A block of mass m is kept on a wedge of mass M The block and wedge both remain at rest rough The force of friction acting on the wedge due to the block kept on the wedge is A mg sin e B mg cos 0 C mg The net contact force between the wedge and the block is A mg sin e B mg cos 0 C mg M C rough D data insufficient D None of these

20 P Q R S ACB is a smooth quarter circular path of radius R Four forces are acting at a particle placed at A F1 is always horizontal F2 is always vertical F3 is always tangential to path F4 is always directed from particle s position to point B Magnitude of all forces are equal to F Column l work done by F is work done by F2 is work done by F3 is work done by F4 is A B P21 Q 031 R432 S 5129 1 2 3 4 Column II F R F R 2 TFR 2 F R 2 A

9 A passenger train of length 60 m travels at a speed of 80 km hr Another freight train of length 120 m travels at a speed of 30 km h The ratio of times taken by the passenger train to completely cross the freight train when i they are moving in same direction and ii in the opposite directions is S 25 a b c 3 d

4 A current loop consists of two identical semicrcular parts each of radius R one lying in the x y plane and the other in x z plane If the current in the loop is i the resultant magnetic field due to the two semicircular parts at their common centre is AIPMT 2011 Hoi 1 TER 2 Hoi Hoi 3 2 2R 2R 4 Hoi 4R

c 740 J d 2 enters in a An electromagnetic wave of intensity 50Wm medium of refractive index n without any loss The ratio of the magnitudes of electric fields and the ratio of the magnitudes of magnetic fields of the wave before and after entering into the medium are respectively given by JEE Main 2019 a n n n n b n n J d 15 5 ids of same length 1 The

Monochromatic light of frequency is 6 0 1014 Hz produced by a laser The power emitted is 2 x 10 W The number of photons emitted on the average by the source per second is 1 5 1014 3 5 1016 AIPMT Prelims 2007 2 5 1015 4 5 1017

Induction and R are placed iding If R R will be directly MP PET 2001 the circuit The OB I is decreasing An inductor L 100 mH a resistor R 1009 battery E 100V are initially connected in series as show in the figure After a long time the battery is disconnecte after short circuiting the points A and B The current in the AIEEE 2006 circuit 1 ms after the short circuit is a e A b c 1 A 1 e A 0 1 A vold L moooooo A B www R A metallic square loop u in a uniform with velocity its plane as shown in the fig a In AD but not in BC b In BC but not in A c Neither in AD nor d In both AD and 18 A conducting rod angular speed wat E with bob of mass m and conduct

A wave travelling in the ve x direction having displacement along y direction as 1 m wavelength 1 2 m and frequency of Hz is represented by T a y sin 10 x 20 t b y sin 2 x 2 t c y sin x 2t d v sin 2x 2 t NEFT 2013

Consider a rubber ball freely falling h 4 9 m onto a horizontal elastic plate Assume that the duration of collision is negligible and the collision with the plate is totally elastic Then the velocity as a function of time and the height as a function of time will be m a b c TV A d 7 X 2 37 47 MA V1

rictionless floor 1 A block of mass M 6 00 kg slides at a constant speed V on a frictionless floor towards a spring fixed to a wall The block gets attached to the free end of the spring on contact The spring gets compressed by X cm and then continues to perform simple harmonic vibrations Take displacement and motion to the right as positive and the initial position of the block on contact with the spring to be x 0 Setup A The speed V 5 00 m s and the spring is compressed by X 12 0 cm Setup B The maximum speed Vmax 10 0 m s and amplitude of vibration of the spring X 24 0 cm a What is the maximum speed of the block in setup A 1 5 00 m s 6 00 m s 12 00 m s 30 0 m s 24 0 m s

S 0 05m is kept 10 5T When the around any of its the coil will be NEET 2019 dy current effect is NEET 2019 etic braking in train heater ws the variation in magnetic flux t with time through a coil Which of the statements given below is not correct AMU Engg 2001 A E D a There is a change in the direction as well as magnitude of the induced emf between B and D b The magnitude of the induced emf is maximum between B and C c There is a change in the direction as well as magnitude of induced emf between A and C ad amf is not zero at B F13 time t in a coil if a

42 A plano convex glass lens 3 2 of radius of curvature R 20 cm is placed at a distance of b from a concave lens of focal length 10 cm of A a What should be the distance a of a point object O from the plano convex lens so that the position of final image is independent of b 1 30 cm 2 20 cm 3 40 cm 4 60 cm elegram pee

There are two coils A and B linked through their magnetic flux The self inductance of coil A is 2 mH while that of B is 8 mH When the current in coil A is reduced from 4 A to 2 A in 4 s Which among the following cannot be the value of average induced emf in coil B X 1 V 0 5 V 1 5 V

Note Always write your final answers in two decimal places 1 Sky and Blue are lifting some weights inside the gym on a Saturday afternoon They were able to lift a barbell with a force a 450 N at a height of 0 7 meters but Blue did the work in just 9 seconds If Sky was able to do the work in 11 seconds prove that Blue is more powerful

When light of wavelength is incident oneg surface the kinetic energy of photoelectron is E To increase the KE of the electron to 2E the incident wavelength must be hch 1 EX hc 3 2 2 4 hc E hc KIN 2

20 180 There is a wire of resistance 440 Q The wire can bear a maximum current of 2 A The wire is to be cut into n number of identical pieces and then connected suitably across 220 V supply sc as to dissipate maximum power The value of n is X2 3

is no flow 6 Radius of an air bubble at the bottom of the lake is r and it becomes 2r when the air bubble rises to the top surface of the lake If the atmospheric pressure is p cm then the depth of the lake is Neglect pressure difference due to surface tension 1 2p cm 2 8p cm 3 4p cm 4 7p cm

at 49 Water flows through a frictionless duct with a cross section varying as shown in figure Pressure p points along the axis is represented by LAS 3 AP X AP X

A uniform disc of mass m can roll without slipping C is the centre of disc and m 3kg k 10 N m The time period of small oscillations is A 0 6T C 0 9T k 1000001 k 100000 m B 0 3m D 0 1

8 Two parallel disks 60 cm in diameter are separated by a distance of 15 cm and completely surrounded by a large enclosure at 100 C The properties of the surfaces are T 540 C 0 7 T 300 C 0 5 What is the net radiant heat transfer with each surface Do not include back side exchange only that from the surfaces facing each other

A particle of negative charge q and mass m moving with velocity Vo enters a magnetic field B as shown in the figure The time for which the particles remains inside the magnetic field is X X 2 m qB qB qB X X n 20 20 X X

The binding energy per nucleon for a deuteron and an a particle are x and x respectively The energy Q released in the reaction H H He Q S A 2 x x C 4 x x A A B 2 x x D 4 x x

A photosensitive metallic surface has work function hvo If photons of energy 2hv fall on this surface the electrons come out with a maximum velocity of 4 x 106 m s When the photon energy is increased to 5hv then maximum velocity of photoelectrons will be AIPMT Prelims 2005 2 2 107 m s 4 8 x 106 m s 1 2 x 106 m s 3 8 x 105 m s

For Questions 13 14 A In a diatomic molecule potential energy of two atoms is approximately given by U r 612P where r is the interatomic spacing and A and B are positive constants Assuming the interatomic force to be conservative the corresponding force law is also called Lennard Jones Law It can be made out from the interatomic force law that atoms exert attractive forces on each other as the separation between them reduces The force law also tells that the force is repulsive at very short separations 14 13 Equilibrium distance between the two atoms in a diatomic molecule can be expressed as 1 6 B A D 28 B B 4A A 2B A B A B A B If the interatomic separation is equal to its equilibrium value what minimum energy must be given to the molecule in order to dissociate it C 1 6 B2 2A B 1 6 4B

1 A glass plate u 1 5 of thickness t is placed in front of one of the slits in a double slit experiment What should be the minimum thickness t which will make the intensity at the center of the fringe pattern zero wavelength of light used 2 2 3 24 22 4 2

A light inextensible straight thread of length 3 2m is placed on a frictionless horizontal floor A small block of mass m 3 kg placed on the floor is attached at one end of the thread With how much constant speed vo in m s the free end of the thread must be lifted vertically upwards so that the block leaves the floor when the thread makes an angle 0 30 with the floor Acceleration of free fall is g 10 m s

76 The resistivity of a potentiometer wire is if the area of cross section of the wire is 4cm the current flowing in the circuit is 1A the potential gradient is 7 5 v m 1 3 x 10 22 m 3 4 x 10 222 m 2 2x 10 22 m 4 5 x 10 22 m

0 Four identical plates of area A and separation d are connected as shown in diagram Each plates of capacitor are in horizontal plane and P Q and R are three points between plates 1 P Q R 2 3 4 E 3mgd A Ife is in equilibrium between plates 2 and 3 then emf of battery is B Ratio of electric field at point P Q and R is 2 1 1 respectively C If plate 3 is shifted upward by d 2 ratio of potential difference between plate 1 and 2 and between 2 and 3 will be 8 3 D ratio of electric field between plate 2 3 and 3 4 will be 4 1 after the shift

3 The moment of inertia of a uniform cylinder of length and radius R about its perpendicu bisector is I What is the ratio e R such that the moment of inertia is minimum 1 3 2 w 2 4 1 3 2 201