Physics Questions

A uniform magnetic field 20 Texists in a gravity free space all over the space on right side of the shown boundary The given circular arc of radius 2 cm made of conducting wire of total resistance 4 9 is rotated around point O at a constant angular speed 2 rad per second Power required to maintain the constant angular velocity is 64 W 128 W A C B D 32 W 16 W cm 60 X X X X X x 20 X X X X X X X X X X X X X

A particles moves along a coordinate axis in the positive direction to the right Its position is given by s t t 2 t 8 a Determine the direction the particle is traveling when s t 0 b Determine the direction the particle is traveling when a t 0 c Determine the intervals when the particle is speeding up or slowing down

Tes a A coil with internal resistance takes 2 5A when connected across 200V 50Hz supply The power consumed by the coil is found to be 450W Find the power factor and inductance of the coil

W t In the system shown in figure the block A is pulled towards right at a constant speed of 1 m s Find speed of block B w r t ground O O A B VA 1m s A B 6 m s 1 m s 2m s D 37m s

les a loop in steady state current I The loop is in air Calculate the magnetic flux density vector at a point P located at the fourth vertex of the square a a P

3 1 kPa 4 Zero 38 A gas takes part in thermodynamic process in which it Destion is heated from same initial state to same final as temperature The processes are shown in indicator diagram as 1 2 and 1 3 Then choose the correct option 1 Q Q 2 3 W W 13 2 Q Q 2 4 Au 0

A hollow cylindrical shell of radius R has mass M It is filled with water having mass m and placed on an inclined plane connected to a spring spring constant k as shown in the figure When it is disturbed it performs oscillations without slipping on the inclined plane a Find the time period of the resulting oscillation b If the water in the given case freezes into ice which is tightly pressed against the inner surface of the cylinder then find the time period of the resulting oscillation M m 0 www X

In the system shown in figure the block A is pulled towards right at a constant speed of 1 m s Find speed of block B w r t ground D O A B V 1m s A B 6 m s 1 m s C 2m s D 37m s

One proton beam enters a magnetic field of 10 T normally Specific charge 10 C kg velocity 10 m s What is the radius of the circle described by it 1 0 1m 2 1m 3 10m

44 A sphere of radius R at temperature T radiates according to Stephan s law at the rate of H J sec R The rate of radiation of a similar sphere of radius at temperature 27 will be Assuming both spheres to be ideal black body 1 Ho 3 4H 2 109 26 4 256H

The light waves having wave equations y 10Sin ot kx and y 5Sin kx oot interfere The ratio of maximum to the minimum intensity of light in the interference pattern is 1 9 1 2 3 1 3 2 1 4 81 1

14 If a graph of T versus M is plotted then mass of the given spring from the graph is equal to 1 point O magnitude of negative X intercept Oslope of the graph O 3 x slope of the graph O 3 x magnitude of the negative X intercept

8 The instantaneous velocity v of a particle starting with the initial velocity vo and moving with uniform acceleration after time t is give be v vo at Prove by integration that the displacement x at that particular instant from an arbitrary origin is x xo vot 1 2 at

wooden cup from an site has an activity of 2 0 Bq The corresponding activity of newly cut wood is 8 4 Bq If the half life of 4C is 5730 years it can be concluded that the age of the cup is A less than 5730 years B between 5730 years and 11460 years C between 11460 years and 17190 years D greater than 17190 years An ancient archaeological

Mobility of electrons in N type Ge is 5000 cm volt sec and conductivity 5 mho cm If effect of holes is negligible then impurity concentration will be 1 6 25 10 5 cm 3 6 10 3 cm 2 9 25 x 10 4 cm 4 9 x 10 3 cm

A parallel plate capacitor formed by square plates of side length separated by a distance d d is filled with a material whose dielectric constant varies linearly from K to 2K along x The capacitance of the capacitor with the dielectric medium will be

Two blocks A and B of masses m and 2m respectively are connected by a spring of force constant k The masses are moving to the right with uniform velocity v 10m s each the heavier mass leading the lighter one The spring in between them is of natural length during the motion Block B collides with a third block C of mass m at rest The collision being completely inelastic Find minimum speed in m s of block A in the subsequent motion Question Type Single Correct Type 1 5

A point mass m is attached on massless rod of length L The rod is hinged frictionless hinge The hinge is constrained to oscillate vertically with harmonic motion h t h cost The only freedom is which measures the angle of rod from vertical Find 1 Lagrangian and 2 the equation of motion Hinge Pistons L h t Grav Y

An airplane is in supersonic flight at an altitude h At what smallest distance a along the horizontal from the observer on the ground is there a point from which the sound emitted by the airplane motors reaches to the observer earlier than sound emitted by plane when it is at point A that is directly above the observer Up velocity of airplane Us velocity of sound S a Question Type Single Correct Type A h O

Two radioactive nuclei having half life periods 20 years and 15 years respectively have initial activities in the ratio 1 2 After how many years both posses equal activity 1 60 3 180 2 120 4 30

Why in the below question we are not using the formula which is given below after finding the phase difference The below given formula is used for finding the resultant i ntensity Please say what are the difference between these two for mula 1 the intensity at the maximum in a young double slit experiment is lo distance between two slits is d 5A where A is the wavelength of light used in front of one of the slit on the screen placed at a distance D 10d 20 03 2017 4074 A4988 5 D Path difference Ax sp sp 5x D D 52 10d 10d Vi 52 501 507 50 25 50 25 2 4 Hence phase diff A Now 1 1 cos cos

A disc of radius 20 cm mass 1kg is rolling with slipping on a flat horizontal surface At a certain instant the velocity of its center is 4 m s and its angular velocity is 10 rad s The lowest contact point is O Find angular momentum about any point on the ground at shown instant 10rad sec P 1 O Question Type Single Correct Type 0 60 4m s

Assertion A Interference obeys the law of conservation energy Reason R The energy is redistributed in case of interference 1 Both Assertion and Reason are true and the Reason is the corre explanation of the Assertion 2 Both Assertion and Reason are true but the Reason is not corre explanation of the Assertion 3 Assertion is true but Reason is false 4 Assertion is false and Reason is tr

Electrons of mass m with de Broglie wavelength A fall on the target in an X ray tube The cut off wavelength o of the emitted X ray is 1 Xo 2 Ao 2mc h NEET 2016 2h mc 3 Xo 4 Xo A 2m c x h

A particle is projected with some speed at an angle of 60 with horizontal and simultaneously a bee starts following the path of particle with san constant speed The list I below gives some quantities involved for the particle and list ll gives some possible values 45 List l 0 Acceleration at highest point of trajectory 11 Magnitude of rate of change of speed at point A 111 Centripetal acceleration at point A IV Centripetal acceleration at highest point Correct match for particle projected is I RIIS III S IV Q I QIP IIS IVQ IRIS III S IVR I QIP III QIV S 4 u 60 P 0 R s T U List II 3 g 2 0 g 2 4g 2g

Identify the correct statement s The centre of mass of an object must be within the object All the mass of an object actually concentrate at its centre of mass The centre of mass of an object can only be moved from rest if there is non zero internal force The total linear momentum of the system as observed from centre of mass frame of reference is alway

In the situation shown a man of mass 60 kg is initially located at the left end of 8 m long trolley of mass 240 kg The system is initially at rest over a smooth horizontal surface The man walks to reach the right and of the trolley at rest over a smooth horizontal surface The man walks to reach the right end of the trolley displacement of the trolley will be A 2 m C 2 4 m Smooth B 1 6 m D zero

W ment section tai The acceleration of the block B in the assuming the surfaces and the pulleys P are all smooth and pulleys and strir light is 3F xm then the value of x is P P2 4m B A 11 B 17 C 7

An electron is in a finite square well that is 0 6 eV deep and 2 1 nm wide Calculate the energy of the lowest state that an electron is allowed to occupy in this well Give answer in eV to 3 sf

y iment y A plane is inclined at an angle of 30 A body is projected from the bottom of the inclined plane at an angle of 60 with the ground at a speed of 20 m s Find the range and time of flight 30 20 m s u 60 30 X A B 4 75 S m 3 3 4 80 S 3 m E 3 75 C 4s m 3 80 D 4s m

A compound microscope with an objective of 1 0cm focal length and eyepiece 2 0cm Focal length of a tube is 20cm Calculate the magnifying power of the microscope i 270 ii 27 iii 140 iv 14

A ball is projected from to of a tower of height 80m with u 50m s at an angle 37 with horizontal Find range time of flight 50ms 80 m 37 A B C D 320 m 8 sec 400 m 10 sec 300 m 8 sec None

If minimum possible work is done by a refrigerator in converting 100 grams of water at 0 C to ice how much heat in calories is released to the surroundings at temperature 27 C Latent heat of ice 80 Cal gram to the nearest integer

View In Engl child with poor table manners is sliding his dinner plate back and forth in SHM with an amplitude of 10 cm on a horizontal surface At a point 6 cm away from equilibrium the speed of the ste is 40 cm s What is the period Os 5 2T

4 A simple pendulum performs simple harmonic motion about x 0 with an amplitude a and time period T The speed of the pendulum at x a 2 will be na 3 3 d T 2T a T b 37 a T c 5 A mass of 2 0 kg is put on a flat pan attached to a vertical spring fixed on the ground as shown in the figure The mass of the spring and the pan is negligible When pressed slightly and released the mass executes a simple 2009 elleeeeeee m harmonic motion The spring constant is 200 N m What should be the minimum amplitude of the motion so that the mass gets detached from the pan take g 10 m s a 10 0 cm b any value less than 12 0 cm

A bob of a simple pendulum has mass m and is oscillating with an amplitude a If the length of the pendulum is L then the maximum tension in the string is cos 0 1 g acceleration due to gravity mg 1 mg 1 mg 2 P m 1 1 D mg A B C

Three forces with magnitudes of 75 pounds 35 pounds and 65 pounds act on an object at angles of 30 45 and 135 respectively with the positive x axis Find the direction and magnitude of the resultant of these forces Round your answers to one decimal place lb magnitude direction O

12 2 There are two identical balls of mass m 0 2 kg are suspended on two threads of The threads are made of the same material and in their vertical position the two balls touch each other If the ball hanging on the longer thread is released from an initial angle 60 P with respect to the vertical then the thread breaks just before the collision What is the maximum initial angle from which this ball can be released to that none of the threads break after the totally elastic collision A Cos D None of these lengths 1m and C tan B sin 7

The extension in a string obeying Hooke s law is y when velocity of wave in it is v If extension is increased to 1 5y then velocity of wave becomes v then 1 v v 3 v 1 5v 2 V 1 22v 4 V 0 75v ange Telegram

What is the meaning of of neutralization 1 poin The heat is given out when 1 mol of O salt is formed from the reaction between acid and alkali O The heat absorbed when acid reacts with a alkali The heat is given out when 1 mol of Owater is formed from the reaction between acid and alkali The heat released when acid reacts

A man of mass M is standing on the platform The platform is executing S H M of frequency f in vertical direction The span of oscillation is L Then the acceleration of the platform at the top of the oscillation is 4 f L A B C 2 f L M 4 f L M

Consider a hydrogen like atom whose energy in nth exicited state is given by En 13 6 Z2 n when this excited atom makes a transition from excited state to ground state most energetic photons have energy Emax 52 224 eV and least energetic photons have energy Emin 1 224 eV The atomic number of atom is a 2 c 4 b 5 d None of these

In an experiment a magnet with its magnetic moment along the axis of a circular coil and directed towards the coil is withdrawn away from the coil and parallel to itself The induced current in the coil as seen by the withdrawing magnet is 1 zero 3 anti clockwise 2 clockwise 4 infinity K COA 3

A train travelling at 20 km hr is approaching a platform A bird is sitting on a pole on the platform When the train is at a distance of 2 km from pole brakes are applied which produce a uniform deceleration in it At that instant the bird flies towards the train at 60 km hr and after touching the nearest point on the train flies back to the pole and then flies towards the train and continues repeating itself Calculate how much distance the bird covers before the train stops olution For retardation of train v u 2as 0 20 2 a 2 a 100 km hr 1 Time required to stop the train v u at 0 20 100t t hr For Bird speed Distance 1 S V x t 60 x 12 km

3 A body freely falling from the rest has a velocity u after it falls through a height h The distance it has to fall down for its velocity to become double is BHU 1999 a 2h b 4h c 6h d 8h

How come certain solid objects are elastic a Because chemical forces are not rigid while they are flexible within limits they oppose deformations b Because physical systems under stress tend to take the shape determined by the equilibrium of their inner parts c Because their elementary parts are connected by t ny coil springs d All of the above are true e Only a and b above are true

8 Consider the arrangement shown in figure distance D is large compared to the seperation between the slits A monochromatic beam of light c wavelength falls on the slit as shown Find th distance x at which the first order bright fringe formed 1 3 Incident ray AD d 3 AD S d l D ak 2 D 2 D d PA O X screen D d

A solid conducting sphere of radius 2R carrying charge Q is surrounded by two point charges Q and 2Q as shown in the figure The electric field at point P due to the induced charges on conducting sphere is 3R R 8 8 2Q 3R

12 Two particles A and B mov velocity and v along two mutually perpendicular straight lines towards intersection point O as shown in figure At moment t 0 particles were located at distance and 1 respectively from O Then minimum distance between the particles and time taken are respectively 2 B 8 12 V t 14 1 vil 4x 12v 1 v 141 1 V 4 1 12 1 2 v v V O 14 1 1 V T 4 v 1 4 v v v 3 V 14 2 1 V 7 4 v 1 V 1

6 Consider two hot bodies B1 and B2 which have temperatures 100 C and 80 C respectively at a time t 0 The temperature of surrounding is 40 C The ratio of the respective rates of cooling R1 R2 of these two bodies at that time will be O 3 2 O 2 3 O 5 4 O 4 5 1 point