Physics Questions

Three identical discs A B and C as shown in the figure rest on a smooth horizontal plane The disc A is set in motion with velocity v after which it experiences an elastic collision simultaneously with the discs B and C The distance between the centres of the latter discs prior to the collision is 7 times greater than the diameter of each disc Find at what value of n will the disc A after the collision stops nd

If the energy input to a Carnot engine is thrice the work it performs then the fraction of energy rejected to the sink is opone 1850 30 Kerala CEE 2015 a 1 3 d 2 3 e 3 4 s with y 1 4 undergoes the adiabatic process of god by 0 5 b 1 4 c 2 5 mer

23 Interference fringes were produced in YDSE using light of wavelength 5000 A When a film o transparent material with 2 5 x 10 3 cm thicknes was placed over one of the slit opening th fringe pattern shifted by a distance equal 20 fringe width The refractive index of f material is 1 1 2 3 1 4 2 0 5 2 1 3 4 1 5

4 A particle of mass m and charge q approaches from a very large distance towards a uniformly charged ring of radius R and charge mass same as that of particle with initial velocity Vo along the axis of the ring as shown in the figure 1 420 What is the closest distance of approach between the ring and the particle Assume the space to be gravity free and frictionless 4 q V 2 2 2 4 TEM VO TWITT m 4 q R Smooth Figure 1 420 B Ring T 394 2 2 m v 4 R

Board Competitive Exams 14 When pressure remaining constant at what temperature will the r m s speed of a gas molecules increase by 10 of the r m s speed at NTP 1 57 3 K 3 557 3 K 2 57 3 C 4 57 3 C

Consider a cube of side a 0 1 m placed such that its six faces are given by equations x 0 x a y 0 y a z 0 and z a placed in electric field given by E x i yi N C Find the electric flux crossing out of the cube in the form of px 10 4 N m C and fill value of p in OMR Sheet

PHYSICS Which of the following statements is are correct about the refraction of light from a plane surface when light ray is incident from denser medium C is critical angle T A The maximum angle of deviation during refraction is 2 C it will be at an angle of incidence C PHYSICS B The maximum angle of deviation for all angles of incidence is 2C when angle of incidence is slightly greater than C C If angle of incidence is less than C then deviation increases with increase in angle of incidence D If angle of incidence is greater than C then angle of deviation decreases if angle of incidence is increased

3 3 x 10 c 4 Data is insufficient A metallic tape gives correct value at 25 C A piece of wood is being measured by this metallic tape at 10 C The reading is 30 cm on the tape the real length of wooden piece must be 1 30 cm 3 30 cm 2 30 cm 4 Data is not sufficient

15 The massless inextensible string connecting the slider A and mass B passes over two small massless smooth pulleys one of which is attached to A One of the ends of string is attached to mass B and the other to a fix point P on roof as shown in figure Mass B has a constant velocity vo directed downward At the instant when yA b the magnitude of acceleration of A is given b 1 m and v 2 m s In S I unit YA 18 V

NEWTON S LAWS 25 Two blocks connected by a cord passing over a small frictionless pulley rest on frictionless planes as shown in the figure a Which way will the system move b What is the acceleration of blocks c What is the tension in the cord 100 kg 30 53 50 kg

Q 13 Titania the largest moon of the planet Uranus has the radius of the earth and the mass of the earth What is the average density of Titania Data G 6 67 10 Nm kg R 6 38 10 m M 5 97 x 1024 kg a c 2300 kg m 2700 kg m b d 3 1900 kg m 1700 kg m A

Three blocks 1 kg 4 kg and 2kg are placed on a smooth horizontal plane as shown in the figure Find a the acceleration of the system b the normal force between 1 kg block and 4 kg block c the net force on 2 kg block 120 N 50 N

3 How can neutrons be accelerated Give relevent and correct answer because wrong answer gives u downvote LJ

A capacitor has square plates each of side a making an angle with each other as a a0 Find the shown in fig for small 9 the capacitance C is given by C value of n CATHE SRAM the

A massless string pulls a man of 50 kg upward against gravity The string would break if subjected to a tension greater than 600 N What is the maximum acceleration with which the mass can be moved upward

Two blocks shown in figure are connected by a heavy uniform rope of mass 4 kg An upward force of 200 N applied as shown a What is the acceleration of the system b What is the tension at the top of heavy rope c What is the tension at the mid point of the rope 200N 5kg 4kg 7kg

A small object is placed 50 cm to the left of a thin convex lens of focal length 30 cm A convex spherical mirror of radius of curvature 100 cm is placed to the right of the lens at a distance of 50 cm The mirror is tilted such that the axis of the mirror is at an angle 0 30 to the axis of the lens as shown in the figure 50 0 f 30 cm 0 0 50 cm R 100 cm 50 50 3 50 If the origin of the coordinate system is taken to be at the centre of the lens the coordinates in cm of the point x y at which the image is formed are

Is it possible that any battery has some constant non zero value of emf but the potential difference between the plates is zero 1 Not possible 2 Yes if another identical battery is joined in series 3 Yes if another identical battery is joined in opposition 4 Yes possible if another similar battery is

3 Two bodies A and B of same mass area and surface finish with specific heats SA and Sa SA Sa are allowed to cool for given temperature range Temperature varies with time as 1 3 0 0 0 0 A 2 0 0 0 0 0 A B B

C 2 37 In the circuit shown in figure 2 257 the switch S is first closed It is then opened after a long time and then S is closed What is the final charge on C C 3 F A 120 C C 40 C C 6 F B 20V Figure 2 257 B 80 C D 20 C S S

Current is passed through a metallic wire heating it red When cold water is poured over half of its portion 1 Rest of the portion will become more hot 2 Rest of the portion will become cold 3 Whole rod will become cold

4 For larger ball is four times that of the other ball 40 A black body which is at a high temperature T K thermal radiation emitted at the rate of E W m If the temperature falls to 7 4 K the thermal radiation emitted in W m will be 1 E 2 E 4

26 E and E respectively represents the average kinetic energy of a molecule of oxygen and hydrogen If the two gases are at the same temperature which of the following statement is true 1 Eo EH 3 Eo E 2 E E 4 Data insufficient

Hydrogen molecules mass m are in thermal equilibrium at a temperature T Assuming classical distribution of velocity the most probable speed at room temperature is a kgT m b 2k Tlm c 2k T m d m 2k T

At the time of total solar eclipse the spectrum of solar radiation will have A B C D lines A large number of dark Fraunhofer lines A smaller number of dark Fraunhofer lines No lines at all All Fraunhofer lines changed into bright coloured

A ball of mass m is placed on a sledge of mass M The sledge moves on an inclined plane A of angle of inclination 0 Inclined plane A is moving with constant horizontal acceleration a towards left Neglect friction everywhere A Normal reaction force between m M is m gcose asin B Normal reaction force between A M is M m gcose asin C aM A am A gsin0 acos0 2 2 D aMam sin 0 g a a A

Q 14 A swimmer wishes to cross a 500m wide river flowing at 5km hr His speed with respect to water is 3 km hr If he heads in the direction making an angle with the flow find the time he takes to cross the river a c cose 10 sine minutes minutes b d 10 sing cose seconds seconds

a find jerk without going into the causes of motion b find acceleration without going into the causes of motion c find velocity without going into the causes of motion

will cool at same rate 2 A body cools down from 80 C to 60 C in 10 minutes when the temperature of surroundings is 30 C The temperature of the body after next 10 minutes will be 1 30 C 3 50 C 2 48 C 4 52 C

Objective Type Questions A uniform thermometre scale is at steady state with its 0 cm mark at 20 C and 100 cm mark at 100 C Temperature of the 60 cm mark is 2 68 C 4 58 C 1 48 C 3 52 C

JIPMER 2001 02 a 250 N c 1000 N A ball of mass 0 25 kg attached to the end of a string of length 1 96 m is moving in a horizontal circle The string will break if the tension is more than 25 N What is the maximum speed with which the ball can be moved CBSE PMT 1998 b 750 N d 1200 N a 14 m s b 3 m s d 5 m s c 3 92 m s A body of mass 5 kg is moving in a circle of radius 1m with an 61 62 Find the maximum circular track of rac road and tyre is 0 2 a 0 14 m s c 1 4 km s A car when passes which is equal to Mv r a Mg

Board Competitive Exams 41 A sphere a cube and a thin circular plate al made of the same mass and finish are heated to a temperature of 200 C Which of these objects wil cool slowest when left in air at room temperature 1 The sphere 2 The cube

Current through an inductor is increasing according to du 2t Variation of rate of increment of its energy with dt time t is correctly shown in the graph Only one correct answer A B C D du dt 2 du dt C du dt 22 du dt

slow A DIOCK converted into steam at 100 C Which of the following curves best represents the event T 5 1 1 3 t 2 4 4 If is conduc variatio 14 1

from rest and 0 A particle of mass m is follows a parabolic path as shown Assuming that the displacement of the mass from the origin is small which graph correctly depicts the position of the particle as a function of time V x x t A a o x t c 0 1 A x t b o x x t 5 for d of A fr

2 10 A metallic ring was first submerged in water and weighed against a mass of 10 g When the ring was submerged in oil of sp gr 0 8 the balancing weight had the mass of 13 g Calculate the true density of the ring material

In the figure shown a small block of mass m 2 kg moves in fixed semicircular smooth track of radius R 2 m in vertical plane It is released from the top The normal reaction on the block in newtons at the lowest point of track is 10x find x Take g 10m s R

Initially spring is in its natural length and blocks A B are at rest Find maximum value of constant force that can be applied on B such that block A remains at rest g 10 m s give answer in Newton k 100 N m wwwwww A 2 kg H 0 1 B 1 kg H 0 2 F

is false Statement II is true To increase the current sensitivity of a moving coil galvanometer we should 1 decrease number of turns in coil 2 decrease area of cross section of the coil 3 increase torsional constant of spiral springs 4 None of the above 11 4 f 1 sa 2 3 4 34

A loop carrying a current i lying in the plane of the paper is in the field of a long straight wire with constant current i inward as shown in fig Find the torque acting o the loop In N m Given I 1 10 A 0 30 b lm a 0 5m THE NA GROUP

What force parallel to a frictionless plane is necessary so that a 60 0 kg object will slide down the plane wi acceleration of 5 0 m s2 if the plane makes an angle of 60 with the horizontal

from the wire Pick out the WRONG statement 1 The gain in the K E of the electron moving at right angles to the magnetic field is zero 2 When an electron is shot at right angles to the electric field it traces a parabolic path 3 An electron moving in the direction of the electric field gains K E 4 An electron at rest experiences no force in uniform and constant the magnetic field

20 A particle of mass m is released follows a parabolic path as shown Assuming that the displacement of the mass from the origin is small which graph correctly depicts the position of the particle as a function of time V x x t a o x t c 0 O x t b o x x t d o for t

A point object is placed at 30 cm from a convex glass lens n 2 of focal length 20 cm The fina image of object will be formed at infinity if A another concave lens of focal length 60 cm is placed in contact with the convex lens B another convex lens of focal length 60 cm is placed at 30 cm from the first lens 4 C the convex lens is immersed in a liquid of refractive index O 3 9 D The convex lens is immersed in a liquid of refractive index 8

The point group symmetrics of the three molecules shown in Figs 1 3 are respectivel temperature is linear with an intercept Tc H CI CI CI H H Fig 1 notation Cay 2mm a C h C v C h c D C C 1 TL H Fig 2 C2h 2 m H CI H Fig 3 D2h mmm b C C C h 8 C

9 PHYSICS The particle of mass 1 kg is acted upon by a force F F i F from t 0 to 1 4 sec Find the velocity of the particle at t 4 sec if its initial velocity is 1 and the variation of applied force with time is as shown in the graphs Fx N A V 1 1 5 0 2 T sec B V 11 Fy N 5 0 2 C v 10 4 T sec D v 21 10

An empty plastic box of mass m is found to accelerate up at the rate of g 6 when placed deep inside water Hc much sand should be put inside the box so that it may accelerate down at the rate of g 6 Than

4 Move towards ve x axis a current PQ is part of a very long wire carrying a current and passing close to the circular coil If the direction of the current are those as shown what is the direction of force acting on PQ 1 Parallel to PQ towards P At right angles to PQ to the right P O 2 Parallel to PQ towards Q 4 At right angles to PQ to the left

Two blocks of mass 4 kg and 2 kg are attached by an inextensible light string as shown in figure Both the blocks are pulled vertically upwards by a force F 120 N Find a the acceleration of the blocks b tension in the string Take g 10 m s

1 A jet airplane travelling at the speed of 500 kmh ejects its products of combustion at the speed relative to the jet plane What is the speed of the combustion with respect to a observer on ground 1500 kmh 2550 km h 2000 km h b d 1250 km h 1000 km h