Basic Physics Questions and Answers

D A particle is released from rest at the point x a and moves along the x axis subject to the potential energy function U x shown The particle X b C d 1 moves to a point to the left of x e stops and remains at rest 2 moves to a point x e and then moves to the left 3 moves to infinity at varying speed 4 moves to x b where it remains at rest

2 52 In the figure 2 217 all the surfaces are frictionless What force F is required to be applied on the bigger block so that m2 and m3 will remain at rest on it 2020 of faspo Dailgas m2 m3 tipolov m2

of a hill is being observed by a person at some distance as shown in the figure It is evening and the sun has just set behind the hill Consider regions I and II of the smoke going up the sky SUN Hill Comple Ohand 7777 a region I will be slightly brighter than the hill and region II will be slightly brighter than the sky b region I will be slightly darker than the hill and region II will be slightly brighter than the sky c region I will be slightly brighter than the hill and region II will be slightly darker than the sky region I will be slightly darker than the hill and region II will be slightly darker than the sky

o 1 In case if selected typed option is incorrect o 0 In case if no response is typed selected A ball of mass m moving with a kinetic energy 3 J undergoes a head on elastic collision with another stationary ball of mass 2m During the impact the potential energy of the system can be 3 J O can be 2 5 J O can be 2 4 J O can be 2 J

7 the speed of the charged particle in a cyclotron is increased by O O O O neither electric field nor magnetic field O electric field only both electric field as well as magnetic field 1 pc O magnetic field only

A man starts driving in an open gypsy at t 0 in rainy weather Assume that speed of gypsy varies with time as v kt At t 1 s he observes rain is falling vertically to him At t 2 s he finds rain drops hitting him at an angle of 45 with vertical Assuming velocity of rain to be constant the angle with vertical at which rain is actually falling is tan x The value of x is

Two concentric shells have radii R and 2R charges q and qa and potentials 2V and respectively Now shell B earthed and charges on them become q and q then B Oz a b 4 1 c Potential of A after earthing becomes V

A light ray is incident on a horizontal plane mirror at an angle of 45 At what angle should a second plane mirror be placed in order that the reflected ray finally be reflected horizontally from the second mirror as shown in figure P7777 S 45 45 C Za N a 45 mmmm

Pls explain in detail The length of the wire between two ends of a sonometer is 100 cm What should be the positions of two bridges below the wire so that the three segments of the wire have their fundamental frequencies in the ratio 1 3 5 a 1500 23 300 23 cm 500 23 cm 1500 cm 23 cm b d 1500 23 300 cm cm 23 1500 23 cm 2000 23 cm

A block can slide along incline plane as shown in figure The acceleration of chamber is g m s horizontally as shown Find 3 2 the time when the block collide with the vertical wall AB of the chamber take g 10 m s A 15 sec C 2 sec B 2 sec 2 D sec 20 m m 60 B

Two plane mirrors are parallel to each other and are spaced 20 cm apart A luminous point is placed between them and 5 cm from one mirror Determine the distance from each mirror of the three nearest images in each 2 20 cm cm 15 cm 1

If resultant external force acting on a system of particles is zero then which of the following is are correct Linear momentum of the system is conserved Acceleration of centre of mass of the system is zero Velocity of centre of mass is always zero Change in Kinetic energy of the system is always zero

Please answer D at least The rest of them are correct but would also be nice if you could explain them 1 point Tom is reviewing and analyzing the footage of a long jump event that he participated in In his winning jump he left the takeoff boar with a horizontal velocity of 7 9m s and a vertical velocity of 2 6m s A If Tom s airtime was 0 66 s what was the resultant horizontal displacement of the jump Horizontal Displacement 7 9 0 66 B What was Tom s vertical velocity just before landing his 0 66 s jump Vertical Velocity 3 868 m s m C If Tom s centre of gravity COG was 1 4 m high at takeoff how high will it be at the peak of the jump COM peak 1 744 m m D Where is Tom s COG when he first reaches the sand pit at landing COM 7 9 0 66

Listen 4 A sign board weighing 100 N hangs from a cable shown in Figure The cable makes an angle of 250 with the horizontal Find out the tension in the each cable a 100 N b 50 N c 118 31 N d 84 52 N e none of them a b 25 25

During an isothermal expansion a confined gas does 150 J of work against its surrounding implies that 20 a 150 J heat has been removed from the gas b 300 J of heat has been added to the gas c No heat is transferred because the pro isothermal d 150 J of heat has been added to the gas

Consider the following two statements regarding transformers and choose the correct option Statement A and Is p Statement B For step down transformer Vs Vp so Ns Np and Is Ip For step up transformer Vs Vp so Ng Np Only statement A is correct Only statement B is correct Both statements are correct Neither statement A nor statement B is correct

2 A box of mass 1 kg is mounted with two cylinders each of mass 1kg moment of inertia0 5kg m and radius 1m as shown in figure Cylinders are mounted on their control axis of rotation and this system is placed on a rough horizontal surface the rear cylinder is connected to battery operated motor which provides a torque of 100n m to this vcylinder via a belt as shown if sufficient friction is present between cylinder and horizontal surface for pure rolling find acceleration of the vehicle in belt and other a 20 m 2 S m S 2 Neglect mass of motor accessories of vehicle m Electric meter m 2 m 2 m 2 b 10 c 25 d 30 S S S

Q 49 In the situation shown the distance between the object O and its image is 24 cm The object is 6 cm above water level and the beaker containing water up to 8 cm is kept on a plane mirror Refractive index of the water is Water 1 3 2 3 5 4 TIT 6 cm 8 cm 2 4 3 4 7 Mirror by a

of 6 The critical angle of a ray of light incident at the surface separation of two immscible liquids is 64 48 If the refractive index of a liquid is 1 4 and velocity of light in vacuum is 3 10 0 cm s calculate the probable two values of velocity of light in the other liquid 2 368 x 10 0 cm s n s 1 939 10 cm 1010 s 11

7 Current of 4 8 ampere is flowing through a conductor Then the number of electrons flowing per second through it will be 1 3 x1019 3 6 x 1020 4 3 x 1020 2 6x 1021

1 The angular width of the central maxima of the diffraction pattern in a single slit of width a experiment with A as the wavelength of light is Question Type Single Correct Type 2 3 1 4 3x 2a 2a English 2X a P W Review

A hollow cylinder of radius 4R is rotating about fixed horizontal axis passing through point O with angular velocity A solid cylinder of radius R is rolling without slipping with respect to inner surface of hollow cylinder At the given instant the line OC has angular velocity of 20 Point A and B are topmost and bottom most points of solid cylinder respectively and C is its centre Then at the given instant 200

In the figure shown velocity of the particle at P g 10 m s 1 40 m s 2 30 m s English Question Type Single Correct Type 3 50 m s 40m s 45m Tower Review P

Q 14 MULTIPLE CHOICE Three particles each of mass m can slide on fixed frictionless circular tracks in the same horizontal plane as shown Particle A moves with velocity vo and hits particle B elastically Assuming that B and Care initially at rest and lie along a radial line and the spring is initially relaxed before impact then ma and a hu end ggur aga fag ad fez adusa qals z qy qz fun ag 21 f hem au s B 4 Cz faghazm am h u tu h ku Ma am Tuche ch agd grey faxia A 2R C Vo A The velocity of B immediately after impact is vo E ch gird Uld B i u Correct Answer 5000 B The velocity of C when the stretch in the 200 spring is maximum is 5 Ga f a a Correct Answer Vo m 5k 200 5 The velocity of B when the stretch in the 4v0 spring is maximum is 5 Gafa f ca a Correct Answer 2 4v0 5 2 D The maximum stretch in the spring is Vo

Two vectors a and b add up to a vector c When vector is made 3 times as long and vector b is doubled in length without changing their directions then it is found that vector c is also doubled in length without change in direction Then which of the following is true J K CET 2012 a All three vectors must be parallel b b and c must be parallel to each other but a need not be parallel to b and c c and b must be perpendicular to each other d It is impossible for three non zero vectors a b and c Liet to have the property stated above

A parallel plate capacitor with circular plates of radius Ris being charged with a current as shown in the figure At the instant shown the displacement current between the places enclosed between F 3i 15i 16 R 4 and Ris given by

A uniform rod of mass M and length pivoted at one end such that it can rotat a vertical plane There is negligible frict at the pivot The free end of the rod is h vertically above the pivot and then releas The angular acceleration of the rod whe makes an angle 0 with the vertical is A g sin 0 3g Mg L 2 B sin 0 L

If i j and k represent unit vectors along the x y and between the vecto AMU PMT 200 axes respectively then the angle i j k and i j is equal to a sin 3 c cos b sin 1 d 90 2 3 3

1 If a particle of mass m is moving with constant velocity v parallel to x axis in x y plane as shown in fig Its angular momentum with respect to origin at any time t will be MP PET 2011 a mubk b mubk c mubi d mui b 0 E CI

Vector A has a magnitude of 5 units lies in the xy plane and points in a direction 1200 from the direction of increasing x Vector B has a magnitude of 9 units and points along the z axis The magnitude of cross product AMU Engg 2012 AxB is a 30 c 40 b 35 d 45

A conductor ABOCD moves along its bisector with a velocity 1 m s through a perpendicular magnetic field of 1 Wb m as shown in figure If all the four sides are 1 m length each then the induced emf between points A and Dis Bx A 2 oo 1 41 volt 0 71 volt X None of these X X v 1 m s D X

A bar magnet is moved between two parallel circular loops A and B with a constant velocity v as shown A B A B S N The current in each loop flows in the same direction The current in each loop flows in opposite direction

1 The position of a particle is given by r i 2j k momentum P 31 4j 2k The angular momentum is perpendicular to EAMCET Engg 1998 Kerala PET 2007 a x axis b y axis c z axis d Line at equal angles to all the three axes

91 A boy and a block both of same mass are suspended at the same horizontal level from each end of a light string that moves over a frictionless pulley as shown The boy starts moving upwards with an acceleration 2 5 m s relative to the rope If the block is to travel a total distance 10 m before reaching at the pulley the time taken by the block in doing so is equal to a 8 s c 10 5 S b 4 s d 8 s m 3 10 m 96 Figure show for lifting a is lifted by in case 2 the other F 2 mg of the tv pulley is

A uniform rod AB of mass 2 kg is hinged at one end A The rod is kept in the horizontal position by a massless string tied to point B Find the reaction of the hinge in N on end A of the rod at the instant when string is cut g 10 m s A Nx 0 Ny 5N B Nx 5N Ny 0 SON N 1 10N N 5N String B 19 T S al m 20 1

For the following reaction X YA B at 300 K it is found equilibrium constant equal to 10 Therefore AG AG of the reaction at 300 K respectively are b 17 23 KJ zero a Both are equal to zero c Zero and 17 23 KJ KJ d Both are equal to 17 23

3 0 05 Nm 4 0 025 N m A trolley of mass 20 kg is attached to a block of 7 mass 4 kg by a masseless string passing over a frictionless pulley as shown in the figure If the coefficient of kinetic friction between trolley and the surface is 0 02 then the acceleration of the trolley and block system is Take g 10 m s 20kg KE 1 1 ms2 2 2 m s 4 2 5 m s 3 1 5 ms2 In YDSE with two identical elite when upper elit 8 3 0 05 N m 20 4 0 025 N m arteft f fuiy my aun en surfed get af staf was 0 02 stat am ge faza II AG M Take g 10 m s2 20kg 1 1 3 1 5 YDSE 4kg 2 227 2 4 2 5 2us sur reft feaza un evi mean itz

A thin uniform rod of mass M and length 2R is placed at a distance of 4R from a uniform solid sphere of mass M and radius R The line joining centres of sphere and the rod is perpendicular to the length of the rod as shown in figure M 2R M R DMR K 4R These two masses can experience their mutual gravitational force only Under these conditions If acceleration of sphere towards the rod is calculated to be then the value of B 2A is A B are in simplest form GM AJB R2

A body is projected with a velocity of 20 ms in a direction making an angle of 60 with the horizontal Calculate its 1 position after 0 5 s and ii velocity after 0 5 s Ans i x 5 m y 7 43 m

The coercivity for a certain permanent magnet is 4 0 x 104 A m This magnet is placed inside a long solenoid of 40 turns cm and a current is passed in the solenoid to demagnetize it completely Find the current 10 A 20 A 30 A

A cyclotron is used to accelerate protons deuterons a particles etc If the energy attained after acceleration by the protons is E the energy attained by a particles shall be AMU PMT 2009 a 4E c E The radius of curvature of the path of the charged particle in a uniform magnetic field is directly proportional to b 2E d E 4

Salmon often jump waterfalls to reach their breeding grounds Starting downstream 3 4 m away from a waterfall 0 464 m in height at what minimum speed must a salmon jumping at an angle of 31 8 leave the water to continue upstream The acceleration due to gravity is 9 81 m s Answer in units of m s

A certain vector in the xy plane has an x component of 12 m and a y component of 8 m It is then rotated in the xy plane so that its x component is halved Then its new y component is approximately J K CET 2012 a 14 m c 10 m b 13 11 m d 2 0 m

For the following draw the Lewis structure identify the electron domain geometry molecular geometry and bond angles present You may complete this quiz on a separate sheet of paper and upload a scan photo of your answers Formula Lewis Structure XeFa COCI BF3 AIH Electron Domain Geometry Molecular Geometry Bond Angle s Present

Cross sectional view of a A current i uniformly distributed over cross section is flowing along the length Now a cylinder of radius is cut out of this Then R 2 1 Magnetic field at the centre of both cylinders is same both in magnitude as well as direction 2 Magnetic field at the centre of both the cylinders is same in magnitude but opposite in direction 3 Magnetic field at the centre of both cylinders is same in direction but unequal in magnitude 4 Magnetic field at centre of both cylinders an neither same in magnitude nor in direction

convex lenses Ol Tocal lengths 1 12 are separated by distance f f A parallel beam of circular cross section intensity I enters through the lens having focal length f The intensity of emerging beam will be f f 1 1 NTVN 2 2722 1

7 A circular platform is rotating with a uniform angular speed counter clockwise about an axis passing through its centre and perpendicular to its plane as shown in figure A boy of mass m walk radially inwards with a uniform velocity v on platform The magnitude and the direction of the coriolis force with respect to the direction along which the boy walks is 1 2 mo v towards his left 2 2 mo v towards his right 3 2 mo v towards his front 4 2 mo v towards his back

A 100 W bulb B and two 60 W bulbs B and B are connected to a 250 V source as shown in figure Now P P and P3 are the output powers of the bulbs B B and B respectively then B 8 250 V 1 P P P 3 P P P B M 1 2 P P P

Satellite A is in a circular orbit of radius r and satellite B in another circular orbit of radius 4 r both revolving around the earth The masses of the satellites A and B are in the ratio 3 1 If the symbols V E u and T represent the speed total energy escape velocity and period of revolution of satellite then O VAVB 2 O EA EB 12 UA UB 2 1 O TATB 8

2 If k and k are the real and imaginary parts of the complex wave number k for a dispersive medium for electro magnetic wave propagation then the absorption coefficient a and the refractive index n of the medium are given by symbols have their usual meanings 1 a 2k n ck w 2 a 2k n ck w 3 a k n ck w 4 a 2k n ck w sharya