Basic Physics Questions and Answers

The position of an object is given byr 2t i 5tj 3 k where t is in second and ris be in metres Calculate magnitude of velocity v t at t 2 s A 5 6 m s B 24 5 m s C 16 8 m s 222m a

1 The solution of the Schrodinger equation for a free particle of mass m in one dimension is x t A exp x2 a Find the probability amplitude in momentum space at time t 0 and and time t 5 marks

If the frequency of a particle performing circular motion increases from 60 rpm to 180 rpm in 20 seconds its angular acceleration is O O 6 284 rad s 3 142 rad s

In a potentiometer experiment 2 points a cell is balance by length of 9 120 cm When a cell is shunted by a resistance of 5 Q2 the balancing length is 80 cm The internal resistance of cell is a 2 5 b 50 c 3Q d 4 Q O 2 50 O 50 40 30

A particle is performing a uniform circular motion Ife is the angular displacement then starting from 0 0 the maximum and minimum changes in the momentum will occur when the values of 8 are respectively O 0 and 90 O 90 and 180 O 180 and 270 C 180 and 360

3 If in a hydrogen atom radius of n h bohr orbit is r frequency of revolution of electron in n orbit is f and area enclosed by the n orbit is A then which of the following graphs are correct D T A C log 4 n logn B D log L log 4 logn n

rth Find height 6 51 A satellite is in a circular polar orbit of altitude 300 km Determine the separation d at the equator between the ground tracks associated with two successive overhead passes of the satellite Ans d 2520 km

1 decay occurs only when stability 2 B decay occurs only when ZIN N Z is too small for is too large for stability 3 In decay z decreases by one N increases by one 4 All of these

A very long solenoid perpendicular to the page generates a magnetic field in to the page whose magnitude increases with time Two bulb A and B connected by a wire is glowing due to induced current in loop Now two points diametrically opposite are shorted with another wire lying to the right of bulb in the plane of page After the shortening wire is inserted A Bulb A goes out C Bulb B goes out X X X x x X X B Bulb A gets dimmer D Bulb A gets brighter

The Lagrangian for a three particles system is given by L n n a n n n n M where a is real Then one of the normal coordinates has a frequency w given by a w a b w a 2 c w 2a d w 2

or h 245 20 m 12 25 m Assertion A quick collision between two bodies is more violent than a slow collision even when the initial and the final velocities are identical Reason The rate of change of momentum is greater in the first case AIIMS 2014

The height of a hill at a point x y in metres is given by h x y exp 2xy x 2y 4x 8y 1 where x and y are in km with respect to a certain origin a where is the top of the hill located b what is the unit vector in the direction of steepest ascent at the orig

1 What is the acceleration of a tricycle initially moving with a velocity of 5 m s going down the slope of a hill as it approaches the foot of the hill after 20 seconds its velocity changes to 5 m s

24 A simple pendulum of length I and mass m initially at its lowest position It is given minimum horizontal speed necessary to move i circular path about the point of suspension tension in the string at the lowest positon of bo 2 4mg 4 6mg 1 3mg 3 5mg

by a 15 Two regular bus service with a bus leaving i either direction every T minutes A man cycling with a speed of 20 km h in the direction from A to B notices that a bus goes past him every 18 min in the direction of his motion and every 6 min in the opposit direction The speed with which assumed constant buses ply on road is NCERT Pg 56 1 40 km h 2 60 km h 3 75 km h M 4 80 km h 17 18 Graphically derivative coefficient means differential NCERT Pg 61 Angle made by the line joining two points on the curve with x axis 2 Slope of the tangent line at any point o the curve or 3 Area enclosed under the curve 4 Both 1 and 3 A police van moving on a highway wit speed of 30 km h and a thief s car speec 1 The study of motion of objects ala called rectilinear motion 13234

In an ink jet printer an ink droplet of mass m is given a negative charge q by a computer controlled charging unit and then enters at speed v in the region between two deflecting parallel plates of length L separated by distance d see figure below All over this region exists a downward electric field which you can assume to be uniform Neglecting the gravitational force on the droplet the maximum charge that can be given so that it will not hit a plate is close to 1 mv E dL E L 2 mv d EL

2015 ically 2 in 015 ch 3150 A ligh aveling from air into a medium Velocity of light in a medium is reduced to 0 75 times the velocity in air Assume that angle of incidence i is very small the deviation of the ray is MH CET 2015 a i c 15 4 The u plane is the bound b d 1 3 1 4 3i 10 A point source 3 wor block of height 10 mm figure It is found that the liquid forms a on the top of the block The 01

Which of the following is not a function of the Output Unit a It produces results that can be easily understood by the user b It accepts the results produced by the computer c it supplies the data and instructions to the outside world d It supplies the data and instructions to the computer for further processing

Two masses both equal to 100 g are suspended at the ends of identical light strings of length 1 0 m attached to the same point on the ceiling see figure At time t 0 they are simultaneously released from rest one at angle 0 1 the other at angle 0 2 from the vertical The masses will collide 1 at 0 0 0 0 50 s later 2 at 0 5 0 to the right of the vertical 0 16 s later 3 at 0 0 0 0 13 s later 4 at 0 5 0 to the right of the vertical

A rectangular tank filled with water is moved horizontally with the acceleration half that of acceleration due to gravity Determine equation for free surface of water in the tank Also draw the figure showing hydrostatic gradient lines

Motion on Inclined Plane A metallic block of mass 2 kg is placed on the horizontal surface The block is going to slide down as the plane surface is inclined at an angle of 15 Calculate the coefficient of friction between the surface and the block tan 15 2 3 101 Sol

98 The figure shows 3n cells connected in series to form a circuit r is the internal resistance of each cell and e is the emf of each cell If polarity of n cells are reversed find the terminal voltage across A E 2n cells n cells 11 11 2 Zero 101 102 103

Three students make measurements of the length of a 1 50 meter rod Each student reports an uncertainty estimate representing an independent random error applicable to the measurement Alice A single measurement using a 2 0 meter long tape measure to within 12 mm Bob Two measurements using a wooden meter stick each to within 2mm which he adds together Christina Two measurements using a machinist s meter ruler each to within 11 mm which she adds together The students teacher prefers measurements that are likely to have less percentage relative error Which is the correct order of preference A Christina s is preferable to Alice s which is preferable to Bob s Your Answer B Alice s is preferable to Christina s which is preferable to Bob s CAlice s and Christina s are equally preferable both are preferable to Bob s Correct Answer Christina s is preferable to both Alice s and to Bob s which are equally preferable

A person is running at his maximum speed of 2 m s to catch a train When he is 6m from the door of the compartment the train starts to leave the station at a constant acceleration of 1m s Time taken by him to catch up the train is 1 6sec 2 3 sec 3 4 sec 4 5 sec

A pursuit spacecraft from the planet Zirkon is attempting to catch up with a Trade Federation cruiser As measured by an observer on Zirkon the cruiser is traveling away from the planet with a speed of 0 420 c The pursuit ship is traveling at a speed of 0 730 e relative to Zirkon in the same direction as the cruiser Part A What is the speed of the cruiser relative to the pursult ship Express your answer as a multiple of speed of light VE AZ 2 054

D If the emf of the AC source in the figure is 10 2 sin 100 t where is in volt and t is in second then the expression for the current in ampere in the circuit is R 5Q ww Xc 7Q X 292 moooo

A bar is subjected to tensile loading that varies 40KN in compression to 80Kn in tension The material of bar has a ueild of 400Mpa and an endurance strength of 200Mpa Calculate the cross section area mm 2 of bar for a factor of saftey of 2 5

3 10 and 15 A particle of mass m strikes on ground with angle of incidence 45 and velocity v If coefficient c 1 restitution e 2 1 3 3v 2 V the velocity of reflection is 2 3v V 4 T

10b an electron moves at speed v 100 m s along an x axis in presence of uniform electric and magnetic fields Th magnetic field B is directed into the page and has magnitude 5 00 T In unit vector notation what is the electric field

3 4 F 4 Greater than 4 E The plane faces of two identical plano convex lenses each having focal length of 40 cm are placed against each other to form a usual convex lens The distance from this lens at which an object must be placed to obtain a real inverted image with magnification 1 is 1 80 cm 2 40 cm 3 20 cm ect is at a distan lens real image and a virt respectively having same m length the lens is 1 4 4 3 4 42 2 A concave lens of foc 1 x of the size of th object from the lens 1 x 1 f 3 x 1 x f

The square ABCD made of 4 metal rods AB BC CD and DA with point A and C remain fixed AB and AD have coefficient of linear expansion a and are heated temperature t C BC and CD have coefficient of linear expansion a and are b by 1 C 12 ti So that B and D move on perpendicular bisector of AC The temperature difference is proportional to

A block of mass 2M is attached to a massless spring with spring constant k This block is connected to two other blocks of masses M and 2M using two massless pulleys and strings The accelerations of the blocks are a a2 and a3 as shown in the figure The system is released from rest with the spring in its unstretched state The maximum extension of the spring is xo Which of the following option s is are correct g is the acceleration due to gravity Neglect friction 2M 100000 4 Mg ar qAH7e png M 2M A Xo B When spring achieves an extension of for the first time the speed of the block connected to the spring is 3g 5k C At an extension of of the spring the magnitude of acceleration of the block connected to the spring is 3g D a a a az

An object is placed 0 05 m in front of a concave mirror of radius of curvature 0 15 m Determine the position of the image

In the arrangement shown a and a are the acceleration of the two blocks 1 2 with respect to ground in upward direction of each block with respect to lift Regarding the tension in the string the incorrect statement is m m 1 T mg m a 2 T m g m a 3 T m g a mig Tamia m m dg m m T 2m m my m g a SERIES for Sri Chaitanya Jr ICON Students m2 m 2 m Lift is accelerating TE up with acceleration a m g m a m g m 09 M 147 2m

i The potential energy function for a simple harmonic oscillator is U x kx What is the equilibrium position of the system Explain whether it is a position of stable unstable or neutral equilibrium 3

A short linear object of length x lies perpendicular to the axis of a concave mirror of focal length f at a distance u from the pole of the mirror The size of image is 9 7 2

4 cr cm While a moving picture is being screened a boy introduced a glass slab of thickness 3 cm and refractive index 5 between the projector and the screen In order to have a clear picture on the screen the screen should e moved through a distance of 1 cm away 2 cm away 2 1 cm nearer 4 3 cm away D d the focal length is

28 Eor a given lens the magnification was found to be twice as large as when the object was 0 15 m distant from it as when the distance was 0 2 m The focal length of the lens is 1 1 5 m 2 0 20 m 4 0 05 m 3 0 10 m

13a Two long parallel copper wires of diameter 2 5 mm carry currents of 10 A in opposite directions a Assuming that their central axes are 20 mm apart calculate the magnetic flux per meter of wire that exists in the space between those axes b What percentage of this flux lies inside the wires

LA wheel with 30 metallic spokes each of 0 7 m long is rotated with a speed of 120 rev min in a plane normal to the horizontal component of earth s magnetic field He at a place If He 0 8 G at the place what is the induced emf between the axle and the rim of the wheel Given 1 G 10 T a 2 46 x 10 volt c 5 76 x 105 volt b 6 28 x 10 d 4 92 x 10 volt volt J K CET

51 Two primary cells of EMF E and E E E connected in series with identical orientation are balanced in a potentiometer The balancing point on eetques potentiometer is obtained at 500 cm When polarity of 2nd cell is reversed the balance point is obtained at 100 cm The ratio of EMF of two cells E E is 1 1 1 3 3 2 2 5 1 4 2 5

A car travels with a uniform velocity of 25 m s for 5 s The brakes are then applied and the car is uniformly retarded and comes to rest in further 10 s Find i the distance which the car travels before the brakes are applied ii the retardation

A concave lens forms the image of an object such that the distance between the object and image is 10 cm and the maginfication produced is The focal length of the lens will be 1 4 2 44 cm D 1 22 cm 3 10 cm 4 4 4 cm inn is to be obtained on a parallel wall with

5 An ac current consists of a 220 2 resistor and a 0 7 H choke Power absorbed from 220 V 50 Hz source connected in this circuit if resistance and choke are in parallel is a 110 W b 220 W c 200 W d zero

8 The force experienced per unit length by a conductor carrying a current 5A placed at an angle of 30 degree with a magnetic field of 20 mT is O 1N m O 0 5N m O 0 1N m O 0 05N m 2p

A cylindrical rod 380 mm 15 0 in long having a diameter of 10 0 mm 0 40 in is to be subjected to a tensile load If the rod is to experience neither plastic deformation nor an elongation of more than 0 9 mm 0 035 in when the applied load is 24 500 N 5500 lbf which of the four metals or alloys listed below are possible candidates Show calculations and justify your choice s Material Aluminum alloy Brass alloy Copper Steel alloy E Oys GPa MPa 70 255 100 345 250 450 110 207 OTS MPa 420 420 290 550

Two identical circular coils A and B are kept on a horizontal tube side by side without touching each other If the current in the coil A increases with time in response the coil B a is attracted by A c is repelled b remains stationary d rotates

3 10 3 watt 4 90 watt 61 Charge on capacitor in steady state is CER 1 R r uestionpaper R R E H C r CEr 2 R r

The radius r and height h of a circular cylinder are related to the cylinder s volume V by the formula V h a If height is increasing at a rate of 5 m s while radius is constant Find rate of increase of volume of cylinder b c If height is increasing at a rate of 5 m s and radius is increasing at a rate of 5 m s Find rate of increase of volume of cylinder If radius is increasing at a rate of 5 m s while height is constant Find rate of increase of volume of cylinder

If not current flows through the galvanometer the find the value of unknown resistance X Assume that resistance per unit length of wire AB is 0 2 cm A X www 60 cm 4V calculate total current given by battery J R 20 www 40 cm B then also