Basic Physics Questions and Answers

A nere inner surface of a smooth spherical shell of radius 6R as shown in figure The masses of the shell and small spheres are 4M and M respectively This arrangement is placed on a smooth horizontal table The small sphere is now released The x coordinate of the centre of the shell when the smaller sphere reaches the other extreme position is 1 R Two y O 2 2R which X 3 3R 4 4R ally at rest nove are as far re 35 X FAC 1 R s fear i a you an fea Y O 2 2R f

A meter scale is kept on a knife edg e at 50cm mark A weight of 20 gf is hanging at 80 cm mark and a weight of 50 gf is hanging at 60 cm mark A weight of 55 gf is hanging at x cm fro m 0 mark Draw the diagram for arra ngement and calculate x

A charged particle having a charge q moves along the x axis with a constant velocity vo Another particle B with charge q and mass m is lying on the y axis at y a The particle B is constrained to move along the y axis while the particle A moves along the x axis Assuming that the velocity v is very large find the impulse imparted to B along the y axis as the particle A moves from to assuming that the motion of particle B is negligible

The equation of a plane progressive wave is y 0 03 sin 8 When it is reflected at a rarer 20 When medium medium with higher velocity at x 0 its amplitude becomes 50 of its previous value The equation of the reflected wave is Question Type Single Correct Type 1 y 0 02 sin 8T X 20 2 y 0 02 sin 87 t t zo 20 3 y 0 015 sin 8 t 4 y 0 015 sin 8 t X 20 X

21 The value of the integral dz z e where C is an open contour in the complex z plane as lm z shown in the figure below is 5 a e e c Ans c 5 b d 5 Q 5 e 1 0 0 1 AC 1 0 R

A point charge q is kept on equatorial position of an electric dipole of dipole moment p at distance r as shown in the figure Electric potential at the centre of dipole is q p p ATEO Zero 4TE p ATE q Arte

One side of a wall is maintained at 400 K and the other at 300 K The rate of heat transfer through the wall is 1000 W and the surrounding temperature is 25 C Assuming no generation of heat within the wall the irreversibility in W due to heat transfer through the wall is

The semi major axis of planet A is four times the planet B The ratio of time periods of revolutions of planets around the sun is 4 1 1 6 2 1

Pactice Paper 3 The density of a solid ball is to be determined in an 26 periment The diameter of the ball is measured with a screw gauge whose pitch is 0 5 mm and there on the main scale is 2 5 mm and that on the circular are 50 divisions on the circular scale The reading scale is 20 divisions If the measured mass of the ball has a relative error of 2 the relative percentage error in the density is a 0 9 b 2 4 c 3 1 d 4 2 a closes should vercom of mass M made of an extensible material the form of a cylinder of 27

Given that mass of the earth is M and its radius is R A body is dropped from a height equal to the radius of the earth above the surface of the earth When it reaches the ground its velocity will be OGM R O GM 1 2 R 2GM11 2 R

A particle is subjected to three forces F F2 and F3 Forces F and F are defined with respect to the x and y axes as magnitude of F 6N magnitude of F 17N a 54 B 69 F Python input F1 mag 6 F2 mag 17 alpha 54 beta 69 F3 Determine the magnitude and direction angley where 180 180 of F to maintain stat equilibrium of the particle Magnitude of F3 N

Two planets are far from any other bodies If the distance between them is doubled what happens o the gravitational force between them a It is doubled b It increases by a factor of 4 It is reduced by half C d It decreases by a factor of 4

In a photoelectric experiment if the anode potential is plotted against plate current then C X V 1 A and B have different intensities while B and C have same frequencies 2 B and C have different intensities while A and C have different frequencies 3 A and B have different intensities while A and C have equal frequencies 4 B and C have equal intensities while A and B have same frequencies

A source voltage of 8V drives the diode in fig through a current limiting resistor of 100 ohm If diode is of silicon and it s forward resistance is 25 ohm the current in circuit is D O 0 0584 A 008 A 0 08 A O Zero ww 1000 SV Marks 4 1

12 Two identical long conducting wires AOB and COD are placed at right angle to each other with one above other such that O is their common point for the two The wires carry 1 and 12 currents respectively Point P is lying at distance d from O along a direction perpendicular to the plane containing the wires The magnetic field at the point P will be AIPMT 2014

1 A bus travelled 23 km 40 South of East 12 km South 3000 m 24 North of East and 7 km North Compute for its resultant displacement 2 As you walked across the room you bumped your 0 5 m tall table As a result your G tech fell to the ground with an initial velocity of 1 32 m s How long did it take for the pen to reach the ground How far is it from the table when it hit the ground

a 72 and 50 c 50 and 28 7 A boy of mass 30 kg starts running from rest along a circular path of radius 6 m with constant tangential acceleration of magnitude 2 m s After 2 s from start he feels that his shoes started slipping on the ground The friction between his shoes and ground i Take g 10 m s2 a c b 60 and 38 d 80 and 58 112 114 b d 113 115

1 If M1 mass of the earth M2 mass of a body R radius of the earth then show that Gravitational potential energy GM1M2 at a height h from the earth surface is GM1M2 R h 2 A body floats in a liquid with 1 4 th of its outside the liquid It is taken to depth d and then released After what time will it reach the surface 3 Calculate total energy of a body suspended with a spring constant 2 Nm 1 if its amplitude is 1 5 cm

Truth table for given circuit is B ABY 0 1 1 0 0 1 1 0 0 0 1 1 ABY 0 1 1 0 0 0 1 1 0 0 1 1 ABY 00 0 1 1 0 1 0 0 0 0 D Y

3 A boy starts from point A and passes point C of a track ABC shown in the figure Portion AB of length is straight and portion BC is a semicircle of radius r r D Anywhere on the track the modulus of the maximum acceleration of the boy is a Find minimum transit time of the boy from A to C A

A mass of 0 98 kg suspended using a spring of constant K 300Nm is hit by a bullet of 20 gm movir with a velocity 3 0ms vertically The bullet gets embedded and oscillates with the mass Find the amplituc of oscillation

A particle is located at the position vector 8 001 9 003 m and a force exerted on it is given by F 6 001 5 001 N a What is the torque acting on the particle about the origin T 14k N m b Can there be another point about which the torque caused by this force on this particle will be in the opposite direction and half as large in magnitude Yes No c Can there be more than one such point Yes No 0 d Can such a point lie on the y axis Yes No e Can more than one such point lie on the y axis Yes No 1 Determine the position vector of one such point Give a point on the y axis

c 24 A liquid of density p is filled in a wide tank to a heighth A solid rod of length L cross section A and density p is suspended freely in the tank The lower end of the rod touches the base of the tank and A Lin where n 1 Then the angle of inclination 8 of the rod with the horizontal in equilibrium position is a sin c sin Po Po b sin Po d sin RC shown in V T diagram is

The sun radiates electromagnetic energy at the rate of 3 9 x 1026 W It s radius is 6 96 x 108 m The intensity of sun light at the solar surface will be in W m 1 4 x 104 2 8 105 4 2 x 106 6 4 x 107 Marks 4 1

Two vibrating tuning forks producing progressive waves given by y 4 sin 500xt and y2 2sin 506nt are held near the ear of a person The person will hear O 3 beats per second with intensity ratio between maxima and minima equal to 9 03 beats per second with intensity ratio between maxima and minima equal to 2 O 6 beats per second with intensity ratio between maxima and minima equal to 2 O 6 beats per second with intensity ratio between maxima and minima equal to 9 Marks 4 1

he kinetic energy of systemis ugh find tum the Mys ving has ic rough figure and the ould be ock so 57 nVPo 25 A cyclic process ABCA shown in 1 T diagram is performed with a constant mass of an ideal gas Which of the following graphs in figure represents the corresponding process on a P I diagram c sin 2 Love c T b d P4 B C

A body of mass 3 kg acted upon by a constant force is displaced by S metre given by relation S 5 2 where t is in second Power of the force is O constant O linearly increases with time 32 Increases with time as Increases with time as 112 Marks

A particle is located at the position vector r 8 001 9 00j m and a force exerted on it is given by F 6 001 5 001 N a What is the torque acting on the particle about the origin T 14k N m b Can there be another point about which the torque caused by this force on this particle will be in the opposite direction and half as large in magnitude Yes No c Can there be more than one such point Yes No d Can such a point lie on the y axis Yes No e Can more than one such point lie on the y axis Yes No samas f Determine the position vector of one such point Give a point on the y axis

Q5 COS O sin 2 cos Refractive index of a medium is u The incidence angle is twice that of refracting angle The angle of incidence is L 2 4 2 T 00 13 600

A small bead can slide without friction on a circular hoop that is in a vertical plane and has a radius of 10 m The hoop rotates at a constant rate about a vertical diameter Find the height of the bead in m above the bottommost point at which bead can be at rest w r to hoop if the angular velocity of rotation is 0 5 rad sec 10m

A charge of 50 C is placed on one of the plates of an isolated paralleled plate capacitor A if capacitance of capacitor is 1 F a potential difference of 50 V is developed between the plated B if capacitance of capacitor is 2 F a potential difference of 50V is developed between the plates 1 C if capacitance of capacitor is uF a potential difference of 50 V is developed between the plates D unless some charge is given to second plate we cannot have potential difference between the plates

c 125 m d 250 2 m 31 The Poisson s ratio of a material is 0 4 If a force is applied to a wire of this material there is a decrease of cross sectional area by 2 The percentage increase in its length is a 3 c 1 b 2 5 d 0 5

18 The refracting angle of a prism is A and refractive index of the material of the prism is cot A 2 The angle of minimum deviation is 2015 a 180 2A c 180 2A b 90 A d 180 3A

If dielectric strength of air is 3 Mv m out of the given options which one is the maximum charge that can be stored on a sphere of radius 10 cm B 3 C A 2 C C 4 C F 5 C A charge of 50 C is placed on one of the plates of an isolated paralleled plate capacitor A if capacitance of capacitor is 1 F a potential difference of 50 V is developed between the plated B if capacitance of capacitor is 2 F a potential difference of 50V is developed between the plates

A particle moves in x y plane according to equations x 4 5 16 and y 5r where x n metre and is in second The acceleration c article is 8 ms2 14 ms a b 12 ms2 d 16 ms2

The average acceleration vector for a particle having a uniform circular motion is V 1 A constant vector of magnitude U 2 A vector of magnitude directed normal to the plane of the given uniform circular motion 3 Equal to the instantaneous acceleration vector at the start of the motion oull vector r

A bird moves with velocity 20 m s in a direction making an angle of 60 with the eastern line and 60 with vertical upward The velocity vector in rectangular form 1 101 10 10k 3 20 10 2j 20k 2 101 10 2 10k 4 10 2 10j k

In an interference experiment third bright fringe is obtained at a point on the screen with a light of 700 nm What should be the wavelength of the light source in order to obtain 5th bright fringe at the same point O 500nm O 630nm O 750nm

The height y and the distance x along the horizontal for a body projected in the vertical plane are given by y 8t 5t and x 6t the initial velocity at t 0 of the body is A 18 m s B C 6 m s 10 m s 4 m s D

A mass weighting 64 lbs stretches a spring 3 inches The mass is in a medium that exerts a viscous resistance of 105 lbs when the mass has a velocity of 6 ft sec Suppose the object is displaced an additional 6 inches and released Find an equation for the object s displacement u t in feet after t seconds u t

There is water in container with a wooden block of density half of water floating at right side of container as shown in the figure O is origin x y axis are shown in figure y 1 2 Ci 3 FO Question Type Multiple Correct Type 10m x x coordinate of centre of mass of water block system is at x 0 y coordinate of centre of mass of water block system is at y 5m y coordinate of centre of mass of water block system is at y 5 m

Complete the statement with always sometimes or never a The pre image and the image of a transformation are b A transformation that is an isometry c An isometry congruent preserves distance maps an acute triangle onto an obtuse triangle

A three phase balanced star connected voltage source with frequency w rad s is connected to a star connected balanced load which is purely inductive The instantaneous line currents and phase to neutral voltages are denoted by ia ib ic and Van Vbn Vcn respectively and their rms values are denoted by V and I If R 9 Van Von Ven 0 1 3 3 then the magnitude of Ris 123 0 3 1 3 0

O O 2 cm A convex lens is placed between object and a screen The size of object is 3 cm and an image of height 9 cm is obtained on the screen When the lens is displaced to a new position what will be the size of image on the screen O4 cm 1 O 6 cm 00 08

A beam of light of wavelength 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away The distance between the first dark fringes on either side of the central bright fringe is O 1 2 cm O 1 2 mm O 2 4 cm

Q 12 moderate 4 1 00 30 A single slit is used to observe diffraction pattern with red light On replacing the red light with violet light the diffraction pattern would O Remain unchanged O Become narrower O O Become broader

9 Assertion In a pressure cooker the water is brought to boil The cooker is then removed from the stove Now on removing the lid of the pressure cooker the water starts boiling again Reason The impurities in water bring down its boiling point 2004

A particle moving uniformly in a straight line covers 13 0 0 3 m in time 2 0 0 1 s What is the velocity of the particle with an error limit A 6 8 0 09 m s B 6 5 0 5 m s C 6 9 0 5 m s 16 5 10 01 m

4 h EN tan B 0 R 0 5 The track in the vertical plane consists of three segments n and coefficient of 2 AB inclined at 0 tan 1 friction merges smoothly into a smooth 4 parabolic track BO given by equation x 4y O is the origin OC smooth semicircular track of radius R 0 5 m The minimum height h in m at which a particle is to be released from rest so that it successfully completes the semicircular travel is Use g 10 ms 2 standable Last explanation was not very und

The temperature of earth is maintained by a dynamic equilibrium between Sun and Earth Sun and Earth can be assumed to be black bodies If the power output of sun is doubled by changing the temperature equilibrium temperature of earth also doubles If the radius of sun doubles without changing its power output its surface temperature would become 1 2 times of initial temperature If the radius of earth doubles without any change in sun its equilibrium temperature would become 2 times If the distance between earth and sun would decrease by a factor of 2 the equilibrium temperature of earth would become 2 times