Physics Questions

A square loop containing an inductor of inductance 4 H and a capacitor of 2F is fixed in the plane of wires infinitely long carrying current I 4t Amp and I 2t Amp as shown in th figure where t is the time in seconds after the circuit was setup Choose the CORRECT option s a A B O L 00000 Maximum charge on capacitor is 4 In 2 T 2u a

42 Two identical blocks A and B are connected with a spring of constant k as shown in figure If block B is moving rightward with speed v then the maximum extension of spring is 1 2 m 5000000 th Smooth 2 2k

Directions The following questions consist of two statements I and II To answer these questions choose any one of the following four responses Codes A If both statements I and II are correct and Statement II is the correct explanation of statement I B If both statement I and statement are correct but statement II is not the correct explanation of Statement I C If statement I is correct but statement II is incorrect D If statement I is incorrect but statement Il is correct Assertion A thin lens is more powerful

3 Friction coefficient between block and inclined plane is H if lift is moving vertically down with constant acceleration a then the value of acceleration a so that block moves down with constant velocity is 1 4 m s2 3 1 m s2 30 a m s 2 2 m s 4 All of these

30 Two masses m and m are connected by a light rod of length If rod is rotating about an axis with angular speed o Such that its kinetic energy is minimum then its K E is 1 1 m m 2 mm 2 m m cs p 1 mm 00 3 2 m m 4 m 0 31 A body is rolling down an inclined plane If K E of rotation is 40 of K E of translation then body is 1 Ring 2 Disc 3 Solid sphere 4 Hollow sphere 32 A sphere cannot roll on 1 Rough horizontal surface 2 Smooth inclined plane 3 Smooth horizontal surface 4 All of these 33 A solid sphere has combined linear and rotation motion as shown in figure The velocity of its centre of mass when it starts pure rolling is R radius of 1 2 i 1 3 j K 4 00 34 A vector P is along positive x axis if Q is another vector such that PxQ is zero then Q should be 1 5 297 35 The component of the vector 2 3j along the vector B 1 is 2 3 5 2 4 10 2 36 What is the power of an engine which can lift 600 kg of water per minute from 20 m deep well 1 2 kW 2 3 kW

36 resistance A ring is made R 12 2 Find the points A and B as shown in should be connected so that the resistance R of the the figure at which a current carrying conductor sub circuit between these points is equal to S 1 11 38 A 1 4 B AIPMT Prelims 20 2 1 2

Two spherical bodies of mass M and 5M and radii R and 2R are released in free space with initial separation between their centres equal to 12R If they attract each other due to gravitational force only then the distance coyered by the smaller body before collision is a 117 5R c 2 5R 6 1 5R d 4 5R 2015 11 71

In digital communication role of Channel encoder is multiple correct answers To convert analog information signal to digital signal To modulate information signal Add redundant bits to digitally converted information code To convert digital signal signal to analog information You can select

7 A 100 eV electron is fired directly towards a large metal plate having surface charge density 2 x 106 C m2 The distance from where the electron be projected so that it just fails to strike the plate is mm

32 Capacity of parallel plate capacitor with a medium of dielectric constant 8 is 12 F If the medium is removed then capacity of the capacitor would be O 96 F O 1 5 F O 0 67 F O 18 F 1

Which is true about aliasing and foldover distortion You can have one or the other but not both Aliasing is a technique to prevent foldover distortion O They are the same thing They are two types of sampling error

lid sphere of radius R has a charge Q distributed in its volume with a charge density p kra where k and a are constants and is the distance from its centre If the electric field at r R 2 is 1 8 times at r R find the value of a

no 21 10 A block of mass 2 kg is redeased from the top of an inclined smooth surface as shown is figure If spring constant of spring is 100N m and block comes to rest after compressing the spring by then the distance travelled by block before it comes to rest is kg 1 Im 2 1 25m 3 2 5m 4 5m 121 0 0 0 00 mal 8 DPP O digoned from roso 450 a height ho lilher loss

1 Zero 2 2 3 3 4 4 34 A body A starts from rest with acceleration a After 2 seconds another body B starts from rest with acceleration a If they travel equal distance in 5th second from the start of A then a a equal to 1 5 9 2 5 7 3 9 5 4 9 7 1 Aakash edical IT JEE Foundations Telegram 38 The acceleration time a t graph of a particle moving on a straight line is as shown a m s Space for Rough Work The corresponding velocity time v t graph will be A N H a 4 1 2 NI t s 43 At a metro station a girl walks up a stationary escalator in time t If she just stands on the moving escalator then escalator takes her up in time t The time taken by her to walk up the moving escalator will be 5 24

a scientist begins with 100mg of a radioactive substance that decays exponentially after 37 hours 50mg of the substance remains How many miligrams will remain after 57 hours

1 x m are placed at the opposite ends of a rigid rod of length L and negligible mass perpendicular to it The position of point P on this The rod is to be set rotating about an axis rod through which the axis should pass so that the work required to set the rod rotating with angular velocity is minimum is given by wo m L m m L m x P 9 2 x m L x m L m m m2 the

6 64 Two satellites S and S revolve around a planet in coplanar circular orbits in the opposite sense The periods of revolutions are T and nT respectively Find the angular speed of S as observed by an astronaut in S when they are closest to each other Ans 2 3 2 n 1 T n 3 1

0 A soccer player extends her lower leg in a kicking motion by exerting a force with the muscle above the knee in the front of her leg She produces an angular acceleration of 30 00 rad s and her lower leg has a moment of inertia of 0 750 kg m What is the force exerted by the muscle if its effective perpendicular lever arm is 1 90 cm

Figure shows a block of mass m placed on smooth surface of wedge of mass M and inclination e Wedge is kept on smooth horizontal surface Find acceleration of wedge when system is released from rest M

If a particle is projected from point p on the inclined plane Speed of projection is u inclination angle of plane is 0 45 and the particle is projected perpendicularly to the surface If the distance OP is Then find the angle at which the particle will hit u 2g the horizontal surface i e find the value of 8 0 45

e diagram shows the displacement time graph for a particle moving in a straight line Find the average speed for the interval from t 0 t 3 sec Displacement m N1 N2 1 24 time sec

A diatomic molecule is made of two masses m and m2 which are separated by a distance r If we calculate its rotational energy by applying Bohr s rule of angular momentum quantization its energy will be given by n is an integer 1 2 3 4 m m n h 2m m r n h 2 m m r 2n h m m r m m n h 87 m1m r

A metallic block with no potential difference applied across it then the mean velocity of free electrons at absolute temperature T is Proportional to T O Proportional to T Zero

12 Which of the following statement s is are incorrect regarding an elastic collision 1 In an elastic collision the linear momentum of system remains constant 2 In an elastic collision the kinetic energy of system remains constant 3 In an elastic collision the final kinetic energy is equal to initial kinetic energy of the system 4 In an elastic collision the final linear momentum is equal to initial linear momentum of the system 13 If both the blocks moving with constant acceleration

The resistances of the four arms P Q R and S in a Wheatstone s bridge are 10 ohm 30 ohm 30 ohm and 90 ohm respectively The e m f and internal resistance of the cell are 7 volt and 5 ohm respectively If the galvanometer resistance is 50 ohm the current drawn from the cell will be NEET 2013 1 0 2 A 2 0 1 A 3 2 0 A

3 A bus moves in the curved path as shown 240 km hour 9 km minute x km 2 15 km hour 0 5 5 1Q Which is its average velocity between the P and Q points of travel O 15 km minute 11 t minute

26 A disc of radius R has a concentric hole of radius R 2 an axis through its centre and perpendicular to its plane is 1 23 MR 1 and its mass is M Its moment of inertia about 2 MR

15 A particle is given an initial speed inside a fixed smooth spherical shell of radius 1 m such that it just able to complete the vertical circle acceleration of particle at instant when velocity becomes perpendicular to initial initially particle is at the bottom 1 10 g 2 g 3 2 g

3 2 4 4 In a vernier callipers length of 10 main scale division is 2 mm If 20 vernier scale divisions coincide with 18 main scale divisions then the least count of the instrument is 1 0 1 mm 3 0 01 mm 2 0 2 mm 4 0 02 mm

A rectangular plot of land measuring 0 45 hectors is represented on a map by a similar rectangle of 5 sq cm Calculate RF of the scale Draw a diagonal scale to read single o metre The scale should be long enough to measure up to 400 metres Show a distance of 235 metre on it

20 A man of mass m is standing at one end of a trolley of mass M and length L placed at rest on a smooth horizontal surface The man starts moving towards the other end and covers distance L then distance moved by man w r t ground is 1 3 mL m M mL M 2 4 ML m M ML m

18 A particle of mass m makes a head on elastic collision with another stationary body of mass m If m rebounds with half of its original speed then m is 1 3 3 3 2 4 2

An object is thrown in vertically upward direction The time to reach maximum height is 9 VC vo vo 9 vo g V 0 T u 6 V 0 a g Ist u a t 3

h a massive metal cylinder of height h 1 m closed on top by a moving piston is an ideal gas On top of the piston we gently put weight The piston immediately dropped by x 2 5 cm over a long time it was seen that the piston comes down another x 1cm Determine the degree of freedom for the molecules of the gas Room temperature is constant gas does not leak out Use binomial approximation

6 Speed distribution of molecules of an ideal mono atomic gas trapped in a vessel is given in the following table Speeds of the molecules number of molecules 10 20 40 20 10 100 m s 400 m s 600 m s 800 m s 1000 m s of this gas is 324 K If all the molecules of speed 800 m s escape from the vessel by what amount will the temperature of the gas Temperature change a Increase by 47 C c Increase by 102 4 C A balloon filled with of 10 g of hydrogen b Decrease by 47 C d Decrease by 102 4 C

6 When some potential difference is maintained between A and B current I enters the network at A and leaves at B When switch S is closed the equivalent resistance between A and B is ohm 20 92 5Q A I S I B

Level 11 In the circuit shown the cells A and B have negligible resistances For VA 12 V R 500 and R 100 2 the galvanometer G shows n deflection The value of VB is 1 12 V R www ww R G AIPMT Prelims 2 6 V LAY 211

For a satellite escape speed is 11kms If the satellite is launched at an angle of 60 with the vertical what will be the escape speed 11 km sec because C escape speed R Radius of earth 2GM X No chan Ru Lox No change of earth Constant change

is equal to initial linear momentum of the system 13 If both the blocks moving with constant acceleration then extension in spring 32 N 1 6 cm 2 12 cm 3 3 cm 4 2 cm 7 kg K 1000 N m 3 kg 72 N

4 0 20 Nm An automobile moves on a road with a speed of 54 km h The radius of its wheels is 0 45 m and the moment of inertia of the wheel about its axis of rotation is 3 kg m2 If the vehicle is brought to rest in 15s the magnitude of average torque transmitted by its brakes to the wheel is 1 10 86 kg m s 2 3 6 66 kg m s 2 wo metal wire 2 2 86 kg m s 2 4 8 58 kg m s

An object 5 cm long and a pencil 10 cm long are placed in front of a pin hole camera such that their images have the same length The ratio of the distances of object from the pin hole to that of the pencil is 1 3 2 2 1 2 3 5 2 4 1 4 000

29 A long straight wire of radius a carries a steady current I The current is uniformly distributed over its cross section The ratio of the magnetic fields B and B at radial distances and 2 a respectively from the a 2 axis of the wire is 1 los a 2 LOT c 4 d

M 21 If a particle of mass m is thrown with speed v at an angle 60 with horizontal then angular momentum of particle at highest point about point of projection 3 mv 16 g mv 3 16 g 2 m 4 3 mv 16 g 3 mv 8 g

a 12 5 10 C E 200 GPa If the rod fitted strongly between the supports as shown in the figure is heated the stress induced in it due to 20 C rise in temperature will be IES 1999 a 0 07945 MPa b 0 07945 MPa c 0 03972 MPa d 0 03972 MPa

In a sample of hydrogen atom all electron are in a particular excited state n when all electrons return to ground state photon with six different wavelength are emitted Which of the following is are incorrect A Out of six different photon only 2 photons have speed equal to that of visible light B If highest energy photon emitted from the above sample is incident on the metal plate having work function 8 eV KE of liberated photo electron may be equal to or less than 4 75 eV C Total number of radial nodes in all the orbital of nth shell are 6 D Total number of angular nodes in all orbital of the n 1 th shell are 3

A luminious object is placed 20 cm from surface of a convex mirror and a plane mirror is set so that virtual images formed in two mirror coincide If plane mirror is at a distance of 12 cm from object then focal length of convex mirror is 1 5 cm 2 10 cm

A bar magnet is situated on a table along east west direction in the magnetic field of earth The number of neutral points where the magnetic field is zero are MP PMT 2004 b 0 d 4 a 2 c 1

1 Rohan and Anirban are students of the same school that is 18 km away from their hostel One day they started from their hostel at the same time with an initial velocity of 29 8 km h At this speed it would take 20 min for them to reach the school on time After 5 min Rohan stopped due to some problem in his cycle Anirban didn t wait for him and moved forward Rohan took another 5 min to repair his cycle He again started with the same initial velocity as he started from the hostel Read the passage carefully and answer the following questions i What value is not shown by Anirban ii At what distance from their hostel did Rohan stop ii What is the required acceleration for Rohan to reach his school on time when he started the second time

A quantity P is given as P A B C4D which brings maximum error in Pis 1 A 2 B 3 C 4 D The quantity

22 A disc is in the condition of pure rolling on the horizontal surface The velocity of centre of mass is Vo If radius of disc is R then the speed of point P is OP OP R 3 1 W 3 7 v P 2 C 30 V 5 v 3