Physics Questions

3 times 12 mes 14 Imagine a narrow tunnel between the two diametrically opposite points of the earth A particle of mass released in this tunnel The time period of oscillation is 1 2 4 R 2 g 2 R

Find the force on the charge q in the Figure shown below The zy plane is a grounded conductor Xx 3d q de 2q y V 0

Question 19 M M 4 00 N M 1 00 At a point P on the screen at distance D from the slits in standard YDSE experiment 3rdmaxima is observed at t 0 Now screen is slowly moved with constant speed away from the slits in such a way that the centre of slits and centre of screen always lie on same line and at t 1 sec the intensity at point P is observed to be 3 of 4 maximum intensity in between 2nd and 3rd maxima The speed of screen can be Correct Answer

1 A box with a mass of 4 00 kg sits on top of a box with a mass of 6 00 kg The coefficient of kinetic friction between the boxes is 0 250 The coefficient of kinetic friction between the bottom box and the table is 0 500 Each box is attached to a string and they are pulled in opposite directions The string attached to the bottom box has a tension of 60 0 N and the string attached to the top box is pulled so the top box stays stationary a What is the acceleration of the bottom box before it slides out from under the top box b What is the tension holding the top box in place

The plane x 0 is uniformly charged with the surface density o 0 and the plane y 0 with the surface density o Find the strength of the electric field in space and sketch the course of the field line

A sphere of radius 0 5 m rolls on the plank without slipping If velocity of sphere and plank is 10 m s and 5 m s respectively as shown then angular velocity of sphere is O Options 30 rad s 10 rad s X 20 rad s 15 rad s 10 m s 5 m s

Mark the correct statement about longitudinal pressure wave A The density variation and the longitudinal velocity of the particles have their maxima and minima at the position of equilibrium of the particles B At the position of maximum displacement the density is at the ambient environment value C Greatest compression occurs at the same time and place where the velocity of the particles is maximum and in direction of wave propagation D Greatest rarefraction occurs at the same time and place where the velocity of the particles is maximum and in direction of wave propagation

Q12 Light is incident on a right angle prism as shown in figure On the hypotenuse of prism a drop of liquid is placed The refractive index of prism is 1 62 The maximum refractive index that the liquid may have if the light is to be totally reflected is 60 90 O A 1 52 O B 1 38 O C 1 40 O D 1 62 Liquid drop 30

At the instant shown in the figure the block A is moving downwards at speed u If the string is tight and the block B moves horizontally the speed of block B is Options B O 20 cose Au towards right Xucos towards right 21 towards right sin e

Derive the e m f equation of a D C generator An 8 pole DC generator has 500 armature conductors and a useful flux of 0 5wb What will be the EMF generated if it is lap connected and runs at 1200 RPM what must be the speed at which it is to be driven to produce the same EMF if it is wave wound

The electric field of a plane electromagnetic wave in vaccum is represented by Ex 0 Ey 0 5 cos quantities are is S I units Find the component of magnetic field associated with the wave os 2 108 t 1 tesla X O 0 17 10 cos 27 x 10 t a tesla O 0 17 x 10 8 sin 2 x 108 t 1 tes O 0 15 x 10 cos O 0 15 x 10 sin 2 tesla x 108 t 1 tesla cos 27 x 108 t 1 with C 3 108 m sec E 0 all 4

Two charges 9 c and 9 c are placed at the points P 1 0 4 m and Q 2 1 5 m located in the electric field E 0 201 the dipole O 25 x 10 7N m O 25 x 10 5 N m O 15 x 10 7N m O 15 x 10 5 N m V cm Calculate torque acting on 4

In a Rutherford a scattering experiment when 1 a projectile of charge Z and mass M approaches a target nucleus of charge Z and mass M the distance of closest approach is r The energy of the projectile is 1 directly proportional to M M 2 directly proportional to ZZ 3 directly proportional to Z 4 directly proportional to mass M a Z 3 4 2 M Fr 1 M x M HIS 2 t M THIS h

A man can swim with a speed of 3m s in still water and river flows at the rate of 5m s River width is 500m 4 A For shortest path journey 0 Tan 3 B For shortest path journery 0 Tan 3 17 C time taken for shortest path journey is 3 36 min 28 D time taken to cross river in shortest time is 2 min 36 Direction of swimming

A boy standing on road has to hold umbrella at 30 with vertical to keep the rain away He throws umbrella and starts running at 10 km hr he finds that rain drops are hitting his head vertically The speed of raindrops w r t ground is 10 km h O 10 3 km h O 15 km h 20 km h

A 4g bullet is fired horizontally with a speed of 300 m s in to 0 8 kg block of wood at rest on a table If the coefficient of friction between the block and the table is 0 3 how far will the block slide approximately 2014 A 0 19 m C 0 569 m B 0 379 m D 0 758 m rough horizontal floor To do so person A pushes it at an

Q7 25 Feb 2021 Shift Imathange mathonga mathongo mathongo Two coherent light sources having intensity in the ratio 2x produce an interference pattern The ratio will be mal 2 2x 1 2 1 zongo max Imax Imin mathongo mathongo mathango 2 2x 1 3 2 2x ngo 2x 1 2z 4 ngomathongemathonga mathongs mathongo mathongo mathongo mathongo mathongo mathongo mathongo mathongo mathongo mathongo

Wave Optics Questions with Answer Keys malt Ampu regthe An unpolarized light beam is incident on the polarizer of a polarization experiment and the intensity of light beam emerging from the analyzer is measured as 100 onge Lumens Now if the analyzer is rotated around the horizontal axis direction of ongo JEE Main 2021 2019 Chapter wise MathonGo

Calculate the de Broglie wavelength of Rb atom at a temperature of T 100 K Assume kinetic energy at temperature T is given by 3kgT 2 where kg 1 38x1023 J K and I amu 1 6605x10 27 kg 4 marks PART C 2 x 10 20 marks

A bomb is projected with a velocity of 5 m s at an angle 8 from the horizontal ground It explodes in two equal fragments at the maximum height One of the fragments comes to rest just after explosion Centre of mass of the fragments falls on the horizontal ground at a horizontal distance x from the point of projection Taking sino and g 10 m s2 the value of x would be 4 5 Ox 24m Ox 24m O x 2 4 m O None of these A

Consider a series RC circuit as in the figure below for which 0 00 MQ C 9 00 u and 8 21 0 V a Find the time constant of the circuit b What is the maximum charge on the capacitor after the switch is thrown closed Inc c Find the current in the resistor 10 0 s after the switch is closed PA

5 Current sensitivity of a moving coil galvanometer is 5 div mA and its voltage sensitivity angular deflection per unit voltage applied is 20 div V The resistance of the galvanometer is 2 2522

1 point A frictionless spring with a 8 kg mass can be held stretched 1 2 meters beyond its natural length by a force of 100 newtons Find the position of the mass after t seconds if the mass experiences a retarding force equal to twice its velocity and it starts at a velocity of 2 m s meters

A wheel rotating at 20 rad s is brought to rest by a constant torque in 4 second If moment of inertia of wheel is 0 2 kg m What is angle rotated by wheel in first 2 seconds 20 rad 25 rad 30 rad 40 rad

A block moving horizontally on a smooth su rface with a speed of 20m s Suddenly expl odes in the ratio 1 2 and lighter part move p erpendicular to initial direction of motion wit h 60m s then find the velocity and direction of motion of heavier part

Figure shows two coherent sources of waves vibrating of phase and separated by a distance of 8 cm P is the nearest point to the axis where constructive interference occurs in a plane and 24 cm from the line joining the sources If S P is 26 cm then the wavelength of the waves in cm is A 4 B 8 C 10 D 16 8 cm S S24 24 cm 14 ca

A weight W rests on the bar AB as shown in figure The cable connecting W B passes over frictionless pulley If bar AB has negligible weight find reaction at A for system to be in equilibrium O O O W L a L a W L a L a W L 2a L a B W

A source emits sound uniformly in all directions A radial line is drawn from this source On this lir determine the positions of two points 1 00 m apart such that the intensity level at one point is 2 C Db greater than the intensity level at the other

and area of shown in the circuit given below Given that resistivities of the wires PA PB Pc and Po are 22 m 62 m 12 2 m and 2 2 m respectively S 12 V H A 4V 122 H M ww 492 B 152 S Then the position of null point is 1 Mid point of wire B when both switches are open 2 Mid point of wire C when both switches are open 3 Right end of wire A when switch S is closed and S remains open

An inductor 20 mH a capacitor 100 F and a resistor 500 are connected in series across a source of emf V 10 sin 314 t The power loss in the circuit is 1 0 79 W 3 1 13 W A metallic rod of mass per unit length 0 5 kg m 2 4 0 43 W 2 74 W

In the Young s double slit experiment the distance between the slits varies in time ashongomothongs d t do ao sinot where do w and ao are mathongo matho constants The difference between the largest fringe width and the smallest fringe width obtained over time is given as mathongo mothongo 2 3 2AD do d a ongo 2ADao d a3 matonge mathongo AD ao mathongo mathongo mathong mathongo mathongo mathongs mothongo mathongo mothong mathongo mathongo mathongamathong

I 10 1 The image of a point source kept at origin O forms at point A due to transparent sphere of radius 10 cm as shown in the figure Here OX is the optical axis of the sphere Now the sphere is t cut into two equal parts along a plane perpendicular to the horizontal axis OX and the plane surface of the left half PRCS is silvered The right half PQSC is removed Now the co ordinate of image of point source O formed by remaining silvered hemisphere will be A 10 cm 0 C 30 cm 0 I 1 40 cm B 20 cm 0 D 40 cm 01 R I I I 10 cm A

Q18 At the instant shown in the figure the block A is moving downwards at speed u If the string is tight and the block B moves horizontally the speed of block B is www w Options X B 20 cose Au towards right ucose towards right 11 towards right sin e

A small ball of mass m starts at a point A with speed vand moves along a frictionless track AB as shown The track BC has coefficient of friction The ball comes to stop at C after travelling a distance L which is h v A h v 2 2 g NA 2 g hvo 2 g 2h v C 2 g B D A B L 2

sin x x x 5 2 7 If f x 5 b 1 ab x 11x 24 a a x 3 x 5 a b e R then denotes the greatest integer function 25 b 6 5 108 c a b x 5 is continuous at 25 36 H x 5 6 b a b 13 d a 17 29 23 b 100 1 0 6 5

Find the maximum height upto which disc can reach on the incline plane when given velocity v horizontally disc is performing pure rolling motion Ohmax Ohmax Ohmax 3v 4g 2v 9 4v 3g To D

0 A particle of mass m falls from a height h upon a fixed horizontal plane with coefficient of restitution e Total time elapsed before it comes to rest 2h 1 e Vg1 e A 2h V g 1 Total distance covered till it comes to rest 1 e 1 2 A h B 1 e BY h J C 2h 1 e Vg 1 h 1 e D D h 1 e Vg 2 2e h 1 e

etween two point masses m and m placed at a distance r is given by object of mass M is divided into two parts which are placed at distance r Find the mass of both parts if gravitation force of attraction is maximum between them 1 Gmim where G is an universal constant An Gm m 3 M 2M w 3 3 3 MM 2 2 2 4 M 3M 4 4 M 4M 5 5

A ball projected from ground at an angle of 45 just clears a wall and ball strikes the ground distance of 6m on the other side of the wall the height of the wall is A 4 4 m C 3 6 m B 2 4 m D 1 6 m 20

A light ray parallel to the x axis strikes the outer reflecting surface of a sphere at a point 2 2 0 Centre of sphere is at the point 0 0 1 The unit vector along the direction of the reflected ray is xi y zk Find the value of yz 8x

III A beam of electron passes undeviated through two mutually perpendicular electric and magnetic fields If the electric field is cut off and the same magnetic field is maintained the electron move in a circular path of radius 1 14 cm determine the ratio e m if E 8 kV m and B 2 x 10 T

Monochromatic light is passed through double slit and interference pattern is observed on screen 2 5 m away The separation between slits is 0 5 mm The first bright fringe is 3 5 mm away from central fringe The wavelength of light used is 600 nm 500 nm 650 nm 700 nm

1 point A frictionless spring with a 5 kg mass can be held stretched 0 4 meters beyond its natural length by a force of 90 newtons If the spring begins at its equilibrium position but a push gives it an initial velocity of 2 m sec find the position of the mass after t seconds meters

G 4 C 4 is 2 uF The foil is attached to both sides of a paper value of a capacitor formed by thin metallic foil having a thickness of 0 015 mm The dielectric constant of the paper is 2 5 and its breadth is 40 mm The length of the foil used is 1 0 34 m 2 1 33 m N 3 13 4 mm 4 33 9 m

a Sound is produced by vibration b When sound travel from a point to another point the particle of medium also travel from one point to another poir c Loudness can be measured in m d Frequency of sound can be measured in per minute Only a Only a and b Only a and d Only a and c

Bon excited to a level by a radiation of wavelength 2 When the ion gets de excited to the ground state in all possible ways including intermediate emissions a total of six spectral lines are observed What is the value of Given h 6 63 10 34 Js c 3 108 ms JEE MAIN 2019 81

A convex lens is made of material having refractive index 1 25 Both the surfaces are convex It if is dipped in a liquid transparent of refractive increase 1 4 it will behaves like A convergent lens O A sheet O A divergent lens A prism

An electron accelerated by a potential difference V 3 6 V first enters a region of uniform electric field of a parallel plate capacitor whose plates extend over a length 6 cm in the direction of initial velocity The electric field is normal to the direction of initial velocity as shown in figure and its strength varies with time as E ax t where a 3200 Vm s Then the electron enters a region of uniform magnetic field of induction B x10T Direction of magnetic field is same as that of the electric field Mass of electron m 9 x 10 31 kg e 1 6 10 1 C Neglect the effect of induced magnetic field e m Vor HIL B Path followed by the electron while moving in electric field is parabolic Path followed by the electron while moving in magnetic field is helical Pitch of holical path of ploctran is 9 mm

Q13 Two point like objects each carrying charge 10Q are separated by a distance d The force between them is F If half the charge on one object is transferred to the other object while at the same time the distance between them is doubled what is the new force between the two objects O A 0 25 F O B 4 0 F O C no change in F D 0 19 F

6 The equation of simple harmonic motion may not be expressed as each term has its usual 14 meaning 1 x Asin et o 2 x Acos oof o 3 xasin cof bcos cof 4 x Asin oot o Bsin 2 0 Aakash Educational Services Pvt Ltd Regd Office Aakash Towe