Physics Questions

2 The number of turns in the primary and 41 secondary coils of a transformer are 5 and 10 respectively The mutual inductance is 25 H If the number of turns in the primary and secondary coils are changed to 10 and 5 respectively then the mutual inductance in henry will be 1 6 25 3 25 2 12 5 4 50 Bol Stara 25 ta af f aparat 1 6 25 3 25 af afde and ges 2 12 5 4 50

The radiation corresponding to 32 transition of hydro gen atom falls on a metal surface to produce photoelectrons These electrons are made to enter a magnetic field of 3x10 T If the radius of the largest circular path following by these electrons is 10 0 mm the work function of the metal is close to a 1 6 eV c 1 1 eV b 1 8 eV d 0 8 eV

SolveLancer Test Which of the following can represent electric field due to a point charge at points X and Y X L Test a I IV b II III c I III d Only I a b C f 3 SolveLancer

2010 3 A tiny spherical oil drop carrying a net charge q is balanced in still air with a vertical uniform electric field of strength 81m x 105 Vm When the field is switched off the drop 7 ms 1 is observed to fall with terminal velocity 2 10 ms 2 viscosity of the air 1 8x 10 5 N sm 2 and the density of oil 900 kgm Given g 9 8 ms 3 AIEEE the magnitude of q is a 1 6 10 C c 4 8 10 9 C b 3 2x 10 9 C d 8 0x C

A smiling face as shown in figure consists of a ring of radius 6 cm with charge 3 C a second thin wire of charge 4 C and in shape of a circular arc of radius 4 cm subtending an angle of 90 at the center of full circle and small electric dipole of dipole moment 6 x 10 21 Cm is placed as eyes 2 cm from central point Then net electric potential at the center is 1 4 5 104 V 2 9 105 V 3 9 104 V 4 4 5 105 V I 6 cm 4 cm

ALLEN Two masses m 2kg and m 5kg are moving 19 on a frictionless surface with velocities 10m s and 3 m s respectively m is ahead of m An ideal spring of spring constant k 1120 N m is attached on the back side of m The maximum compression of the spring will be 1 0 51 m 2 0 062 m m2kgm 5 kg i thi fram 10 m s 3 m s at m m m sit e 3 xi fein k 1120 Nm ere mi xun fenfum 1 0 51 m 3 0 25 m m 2 0 062 m 4 0 72 m V

Given that the density of states related effective masses of electrons and holes in Si are approximately 1 08 m and 0 56 m respectively and the electron and hole drift mobility at room temperature are 1350 and 450 cm V s respectively Calculate the intrinsic concentration and intrinsic resistivity of Si

18 A force F 31 41 N is acting on a point mass 1 kg at a point A 2m 2m Find the 2 angular acceleration of the line OA at this instant m 1 1 rad s 3 rad s A 2 1 1 2 4 1 rad s rad s

5 In which of the following case Interference of two waves is not observed 1 Point Superposing waves having same frequency but different amplitude Superposing waves having same

A plane mirror is placed at the bottom of a tank containing a liquid of refractive index P is a small object at a height h above the mirror An observer O vertically above P outside the liquid sees P and its image in the mirror The apparent distance between these two will be O

Q10 A beam of light strikes a glass sphere of diameter 15 cm converging towards a point 30 cm behind the pole of the spherical surface Find the position of the image if refractive index of glass is 1 5

A light rigid rod connected with two particles masses m and 2m rotates in vertical plane agar horizontal and vertical surfaces shown in the figure The angular momentum of particle 1 relative to 2 1 2mvl Cose mvl 0 m 2m 2 2 mviCose mvl

Momentum of a photon in a beam of light of wavelength 6000 and intensity 100 W m will be 1 23 x 10 27 kg ms 1 2 12 10 27 kg ms 1 1 105 x 10 27 kg ms 1 3 3 x 10 27 kg ms 1

A non conducting sphere of radius 10 cm has a charge 3 mC distributed uniformly throughout its volume A bullet having charge 3 mC and mass 10g fired from the surface of the sphere along the diameter directly towards its centre Assuming the sphere to be fixed and neglecting any forces other than electrostatic force the minimum velocity of the bullet so that it can emerge from the other side of the sphere is a 3 10 m s b 3 x 10 m s c 9 10 m s d 9 10 m s

An object 20 cm in front of a lens forms a sharp image on a film 10 cm behind the lens A glass plate 6 cm thick of refrac tive index 1 50 is placed between lens and film with its plane faces parallel to film At what distance from lens should object be shifted to be in sharp focus on film b 22 cm a 18 cm c 15 cm d 16 cm

18 A proton is fired from very far away towards a nucleus with charge Q 120 e where e is the electronic charge It makes a closest approach of 10 fm to the nucleus The de Broglie wavelength in units of Fm of the proton at its start is take the proton mass m 5 3 10 27 kg hle 4 2 x 10 15 Js C 1 9x 10 m F 1 Fm 10 15 m IIT JEE

In a metre bridge when the resistance in the left gap is 40 and an unknown resistance in the right gap the balance point is obtained at 40 cm from the zero end On shunting the unknown resistance with 30 find the shift in balance point on the bridge wire 66 6 cm 26 6 cm 11 cm 32 cm

A particle is moving along x axis whose acceleration 4 is given by a 3x4 where x is location of the particle At t 0 the particle is at rest at 4 3 m The distance travelled by the particle in 5 s is 1 10 m 2 32 m 2 7ora

a 38 26 A square is made of four rods of same material one of the diagonal of a square is at temperature difference 100 C then the temperature difference of second diagonal 100 0 C d 100 C 2l b 100 l C

In the circuit shown in figure below the cells E and E have e m f 4 V and 8 V and internal resistance 0 5 ohm and 1 0 ohm respectively Then potential difference across cell E and E will be E 0 5 www 4 V ww 4 592 392 www ww 692 3 75 V 7 5 V 4 25 V 7 5 V 8 V 4 25 V 4 25 V 5 0 V 7 0 V 192 www

ALLEN Three identical blocks A B and C each of mass 9 2kg are kept on a smooth horizontal surface Block A is given a horizontal velocity 10m s towards B as shown in figure Block B and C are attached with a spring Find change in velocity of center of mass of system A B C if A collides with B elastically 10m s A 1 5 m s 3 20 m s B00000 C 2 10 m s 4 zero A B a C TH 2kg 8 ferat afara wa A an frangen AB A B C fra 10m s A 1 5 m s 3 20 m s Bars Afera m 10 m s f Bac fint afe en ufania B00000 C 2 10 m s 4 T

In a given N type Si material if donor concentration is one atom per 2 108 silicon atoms Assuming that effective mass of electron is equal to its true mass Find the value of temperature at which Fermi level coincides with the edge of conduction band density of atoms in Si is 5 1028 atoms per m 5x1028

uniform plastic cylinder of mass 2kg and length 0 5m has 20 turns of a light wire wrapped around its middle such that the v orms a rectangular coil with its plane containing the cylinder s central axis The cylinder is placed on a wedge inclined at 37 he horizontal such that the coil plane is parallel to the inclined plane If the coil carries a current of 0 2A find the vertical hagnetic field B that must be applied to maintain the cylinder at rest 0 5m 37

This question concerns a symmetrical lens shown along with its two focal points It is made of glass with n 1 2 and has focal length f Four different region are shown A B Here A 0 x f B f x 0 C 0 x f D f x C Air n 1 F D If an object is placed somewhere in region A in which region does the image appear

a 45 km h A table clock has its minute hand 5 0 cm long The average velocity of c 3 14 x 104 cm s hand between 6 00 am to 6 30 pm is ns 1 a 1 1 x 104 cm s b 2 2 x 10 4 cm s 1 tip of the minute d 3 3 x 104 cm s takes to prom

Q 17 If n 1 then the dependence of frequency of a photon emitted as a result of transition of electron from nth orbit to n 1 th orbit on n will be 1 1 vx n 2 v 1 n

Two blocks A and B of equal mass are connected by a light inextensible taut string passing over two light smooth pulleys fixed to the blocks The parts of the string not in contact with the pulleys are horizontal A horizontal force F is applied to the block A as shown There is no friction F m Ho D the acceleration of A wat 2 times VILL Which of the following is correct B m A the sum of rate of changes of momentum of A and B is less than the magnitude of F B the sum of rate of changes of momentum of A and B is equal to the magnitude of the F C the sum of rate of changes of momentum of A and B is greater than the magnitude of F D the sum of rate of changes of momentum of A and B cannot be determined

Power P of a lens is given by reciprocal of focal length f of the lens i e P When f is in metre P is in dioptre When a number of thin lenses of power P1 P2 P3 are hold in contact with one another the power of combination is given by algebraic sum of the powers of all the lens i e P P P P3 With the help of the following passage choose the most appropriate alternative for each of the following question Two thin lenses are in contact and the focal length of the combination is 80 cm If the focal length of one lens is 20 cm the focal length of the other would be Select an answer A B C D 26 7 cm 60 cm 80 cm 20 cm

30 A uniform disc of radius R having charge Q distributed uniformly all over its surface is placed on a smooth horizontal surface A magnetic field B Kxt2 where K constant x is the distance in metre from the centre of the disc and t is the time in second is switched on perpendicular to the plane of the disc The torque in N m acting on the disc after 15 sec Take 2 KQ 1 S I unit and R 1 metre is N m

Suppose that reflected white light is used to observe a thin transparent coating on glass as the coating material is gradually deposited by evaporation in a vacuum Describe color changes that might occur during the process of building up the thickness of the coating

Solvelancer TestFgure shows sound source of frequency 140Hz and a car blowing horn continuously with same frequency as of sound source Find number of beats heard by boy on bike when he is ut A and car is at B Take speed o sound 360m a Solvencer Test a 4 25Hz b 6 5Hz c 2 73Ha

Energy levels A B C of a certain atom correspond to in creasing values of energy i e E E E If 2 2 and 2 are the wavelengths of radiations corresponding to the tran sitions C to B B to A and C to A respectively then B a 3 2 12 2 2 b 23 2 2 c 2 2 23 0 d 2 2 2 C B 2 23 A

111 Image of sun formed due to reflection at air water interface is found to be very highly polarised Refractive index of water being 4 3 find the angle of sun above the horizon A 34 70 C 37 30 B 36 9 D 35 8

9 The initial velocity of a particle is u at t 0 and the acceleration a is given by af 2 Which of the following relations is valid 1 v u at 2 2 v u 3 at 2 2 3 v u at 5 45 2 4 v 1 5 2 11

Match the entries of column I with the entries of column II Considering all the cases with refrence to real objects and virtual objects also List 1 1 Plane mirror 2 Concave mirror 3 Convex lens 4 Convex mirror Answer 1 2 3 A A A List 2 B B B B A Virtual image B Real image C Erect image D Inverted image C C C D D D D

SolveLancer Test A student has a coil with resistance 20 and inductance 80 mH which is connected with a 10 V battery He obtains a steady state value of the current The time to acquire half of its steady state value is SolveLancer Test a b c d a b C 2 8 ms 3 5 ms 1 4 ms 5 6 ms

18 A square coil ABCD lying in x y origin A long straight wire passing through origin carries a current i 2t in the negative z direction the induced current in the coil is A D y C X

An astronomer observes galaxy A moving away with B 0 55 and galaxy B moving away in exactly the opposite direction with B 0 65 What is the value of for the relative speed of galaxy A with respect to galaxy B Give answer to three significant figures

For the system shown in the figure the pul leys are light and frictionless The tension in the string will be T m 0 2 A mg sin e 3 1 C mg sin 0 m 3 B 2 12 D 2mg sin 0 mg sin 0

Two bodies each of mass mare initially at rest at infinite distance apart Now they move towards each other under gravitational force The relative velocity of approach at a separation d between them is 1 2Gm d 3 C 2 4 4Gm d 2G m

A double convex lens made of a material of refractive index 1 5 and having a focal length of 10 cm is immersed in a liquid of refractive index 3 0 The lens will behave as a converging lens of focal length 10 cm b diverging lens of focal length 10 cm c converging lens of focal length 10 3 cm d diverging lens of focal length 10 3 cm

Find out the surface charge density at the intersection of point x 3 m plar and x axis in the region of uniform line charge of 8 nC m lying along the z axis in free space A 0 424 nC m 2 B 4 0 nC m 2 c 47 88 C m

bulb of 3 3 cm 29 A thermometer has a spheric 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 x 104 cm Ignoring expansion of glass cm far apart on the stem are marks indicating 1K temperature change m

The light reflected by a plane mirror may form a real image Select an answer A B C D if the rays incident on the mirror are converging if the rays incident on the mirror are diverging if the object is placed very close to the mirror under no circumstances

4 16 A coil carrying a current I 10mA is placed in a uniform magnetic field so that its axis coincides with the field direction The single layer winding of the coil is made of copper wire with diameter d 0 1mm radius of turns is equal to R 30mm At what value of the induction of the external magnetic field can be coil winding be ruptured

A charge q appears on H atom due to movement of electrons towards oxygen Taking the separation between H atom and oxygen atom as r calculate the dipole moment of a hydrogen molecule Given that cos 52 5 0 6

SolveLancer Test In the given figure are the bulbs are of same rating Which of the following statement is are correct for the given figure BA 13 If B fuses B glows dimmer ii If By fuses B glows brighter ii If B fuses B3 glows brighter iv If B fuses B glows brighter SolveLancer Test a iii iv b i iii c only 1 d i lv

A farsighted person s least distance of distinct vision is 0 5 m The power of the lens that should be prescribed to enable him to a read a book held at 0 25m is x diopter Find the value of x Write an answer

n a young s double slit experiment slits are illuminated by a monochromatic source of wavelength 6000 A and fringes ar obtained If screen is moved by a distance of 5 cm towards slits change in fringe width is 3 x 10 5 m Then separation between the slits will be 1 mm 1 2 mm 1 5 mm 1 63 mm

Consider a two particle system with particles having 6 masses m and my If the first particle is pushed towards the centre of mass through a distance d by what distance should the second particle be moved so as to keep the centre of mass at the same position 1 2 3 m mi mi m m 4 d DER TEST SERIES JOINT PACKAGE COURSE T UG 2021 13092020 1 2 encari Gian aut a fact ang fer f 3aftafda to ma mi 4 d d mi m m 4 2g and f Space for Rough Work ferg Grie i C 09980MD31032 LTS Pages