Basic Physics Questions and Answers

Consider a book lying on the floor and a string with length 1 2 0m whose one end is attached to the centre of the upper side of book s cover The other end of the string is held in height h 1 2m above the floor Find the coefficient of friction between the book and the floor knowing that the book which is of mass m 1 kg is dragged at constant speed with force of magnitude F 10N Assume that the book does not open and neglect height of book If your answer is x fill value of 3x g 10 m s

A person enters into a circular park of radius r and moves on the circular path for t minutes and reaches at the starting point The angular displacement of the person is 1 Zero 2 T 3 2 T 4 2r

in one 15 The displacement x of a pal dimension is related to time t by the relation x 2 3t where x is in metre and t in second Find the displacement of the particle when its velocity is zero Ans 9 m 100

A vibrator produces the compression of 3 4m moving in the air with the speed of 340m s the frequency and time period of the vibrator is 1 n 480Hz T 0 0020 Sec 2 n 240Hz T 0 0041 Sec T 0 0165 Sec 3 n 60Hz A T 0 0020 Sec n 50Hz

7 A conductor of length and mass m can slide without any X C X friction along the two vertical conductors connected at the top through a capacitor figure A uniform magnetic field B is set up I to the plane of paper The acceleration of the conductor 1 is constant 3 decreases X X X X X X X 2 increases 4 cannot say X X X X X X X X X X X X XX X X X X X X X X X X X

S A 10m long horizontal wire lying along the magnetic east west direction begins to fall with a velocity of 5 0 m s What will be the emf induced in the wire Given H0 3 x 10 4 Wb m 1 5 10 V

17 PQ is an infinite current carrying conductor AB and CD are smooth conducting rods on which a conductor EF moves with constant velocity v as shown The force needed to maintain constant speed of EF is R P IA A LU E b a HC F

3 Optical system consists of plates of refractive index n and thickness d followed by air of refractive index 1 of width d and so on as shown below Determine the ray transfer matrix 1 1 n d d n d d n d 1

Two pendula have time periods T and The 4 start SHM at the same time from the mea position What will be the phase difference between them after the bigger pendulum has completed one oscillation 1 45 3 60 2 90 4 80

10 A coil of inductance 300 mH and resistance 2 Q is connected to a source of voltage 2 V The current reaches half of its steady state value in 1 0 3 s 2 0 15 s 3 0 1 s 4 0 05 s 11 A metal conductor of length 1 m rotates vertically about

Jennie throws her phone upward that weighs 55 Newtons The phone travels at a speed of 4 meters per second m s and reaches its maximum height at 9 5 meters m At what height is the potential energy of the ball equal to the kinetic energy of the ball Round to the nearest hundredth if necessary

Which of the following is not an application of conservation of linear momentum 1 While firing a bullet the gun must be held tight to the shoulder 2 When a man jumps from a boat to the shore 3 A rocket explodes on midway from the ground Figli 4 A body suspended from the hook of a spring balanced in a lift which is accelerating downward

8 A conducting ring of radius r is rolling without slipping with a constant angular velocity figure If the magnetic field strength is B and is directed into the page then the emf induced across PQ is X X 1 Bor 3 4Bwr X X X X XXX XX X X X X X X X X XQX 2 XPX 4 X X X 2 Bor 2 r Bw 13

ntal half ring can be given as 2 M TR x dx can be given by integrating m R to R as iv Find moment of inertia of a hemisphere of mass M shown in figure 5 28 about an axis AA passing through its centre of mass to e br 00 83 320 MR Lecaq Bixa ori sd R TO M A Figure 5 39

are in the ratio 1 3 5 s docs google com forms d 10T14 2NW7po1y3416jbj0thxxoFmz2mA 210 yLrc edit 21 4 51 PM 44 i Ratio of their area of cross section is Mark only one oval 5 25 1 25 5 1 1 5 25 5 1 25 00 HALF YEARLY EXAMINATION 45 ii Ratio of their electrical resistance is Mark only one oval 1 15 125 01 3 5 1 point 1 points

1 300 kg car traveling initially with a speed of 25 0 m s in an easterly direction crashes into the rear end of a 9 500 kg truck moving in the same direction at 20 0 m s see figure belo he velocity of the car right after the collision is 18 0 m s to the east 25 0 m s 20 0 m s Before 18 0 m s Enter a number b How much mechanical energy is lost in the collision X J Account for this loss in energy After a What is the velocity of the truck right after the collision Round your answer to at least three decimal places m s east V

Fill in the table with time instantaneous velocity and instantaneous acceleration Show your work and the calculations for these values below the table Position m 0 10 20 30 40 50 Time s 0 2 4 4 5 1 6 3 7 5 Velocity m s Acceleration m s

Four point charges q 2 C B 5 C 9c 2 C and qp 5 C are located a the corners of a square of side 20 cm 1 cyclic order What is electric force on charge of 1 C placed at the centre c square NCERT Pg 4 1 0 9 N 3 0 6 N 2 Zero 4 2 4 N

For the potentiometer circuit shown in figure points X and Y represent the two terminals of an unknown emf A student observed that when the jockey is moved from the end A to the end B of the potentiometer wire the deflection in the galvanometer remains in the same direction What are the two possible faults in the circuit that could result in this observation A X Y OG B If the galvanometer deflection at the end B is i more ii less than that of the end A which of the two faults listed above would be there in the circuit Give reasons in support of your answer in each case

PLS EXPLAIN IN DETAIL THE APPROACH TO THIS Q SOLVE ALL STEPS AND JUSTIFY THEM IN WHICH CASES DO WE NEED TO USE NEBULA VECTOR p ls pls PROVIDE SOME EXAMPLES OF Q how does nebula vector help here IS THERE ANY ALTERNATIVE APPRACH I F YES pls pls PROVIE THE SAME 23 The temperature of a point in space is given by T x y z A mosquito located at 1 1 0 desires to move in such a direction that it will get heat as soon as possible then unit vector in direction the mosquito should move is 1 3 IS IS j 2 2 4 i j k 3 YE JIT

12 A sonometer wire resonates with a given tuning fork forming standing waves with five antinodes between the two bridges when a mass of 9 kg is suspended from the wire When this mass is replaced by a mass M the wire resonates with the same tuning fork forming three antinodes for the same positions of the bridges The value of M is a 25 kg c 12 5 kg THOOT b 5 kg d 1 25 kg

Plate current will be maximum when a grid is negative while anode is positive b both the grid and anode are positive c grid is positive while anode is negative d both the grid and anode are negative

Three infinitely long conductors carrying currents I1 I2 and 13 lie perpendicular to the plane of the paper as shown below C31 C 13 C If the value of integral B dl for the loops C C and C3 are 2 0 4 o and o in the units of N A respectively then 1 I 3 A into the paper I1 2 12 3 A out of the paper 3 I3 0 4 I3 1 A out of the paper

diagram a process is given by straight line as shown in figure During the process Given TB TA ot AP A 3Po Po V B V V ess 81091 VS 1 Temperature decreases 2 Temperature increases continously 3 Temperature first increases then decreases 1 Roth 2 and 3 or possible

31 A block A of mass 3kg and another block B of mass 3 kg are connected by a light inextensible string as shown in the figure If the coefficient of friction between the surface of the table and A is 0 6 the maximum mass C to be placed on A so that the system to be in equilibrium is B

A polythene piece rubbed with wool is found to have negative charge of 3 2 x 10 6 C The number of excess electrons on polythene is NCERT Pg 467 1 2 1013 3 5 5 x 10 2 4 1012 4 6 1020

5 Which of the following current must be zero in an unbiased pn junction diode a Current due to majority charge carriers both electrons and holes b Current due to minority charge carriers both electrons and holes c Current due to majority and minority charge carriers d Current due to majority and minority charge carriers only holes 2012

4 Figure shows a small loop carrying a current The curved portion is an arc of a circle of radius R and the straight portion is a chord to the same circle subtending an angle 0 The magnetic induction at center O is 0 360 32 a 3 8 3 5x20x9 8 150x9 0 then outorands 1 Zero 2 Always inward irrespective of the value of 0 Inward as long as 0 is less than WRO 4 Always outward irrespective of the value of 0 two close parallel

A cylindrical vessel containing a liquid is closed by a smooth piston of mass m If A is the cross sectional area of the piston and Po is the atmospheric pressure then the pressure of the liquid just below the piston is 1 Po 2 Po mg A mg A 4 Data is not 3

Cr pcc Displacement area under graph Acceleration tane Increasing Din ve Ace ve be 0 90 UAL CAMERA by vendeep Mono t ve Decre que 5 Velocity decreases X Decreasing ve acceleration Acceleration time graph From a t graph we can 100se Breil Dis ve ACC Incacs Acceleration tane Positive decreasing area under graph Displacement of Calculate otion 8 90 Inc t 6 Velocity decreases Increasing ve acceleration C ince 7031 07 27 23 07

After a ball is dropped the rebound height of each bounce decreases The equation y 5 0 8 shows the relation ship between the number of bounces x and the height of the bounce y for a certain ball What is the approximate height of the fifth bounce of this ball to the nearest tenth of a unit

12 PLS SOLVE WITH ALL STEPS AND PROVIDE REASON OR EACH STEP How to find the potential of B explain clearly 95 Consider three concentric metallic spheres A B and C of radii a b c respectively where a b c A and B are connected whereas C is grounded The potential of the middle sphere B is raised to V then the charge on the sphere C is A 4EV be c b bc c b B 48 V C 4TEV D zero ac cia

Magnetic field at point P due to following current distribution is a 10 a a a a Mo I Tur c b 10 Mo I 2 r a MI a Ho I 90 Tr r 90 2 a a 2 2 a P b d Ho la b Hola 2 r P QUA THRE Ho la Tr Ta 11

ALLE 131 Electromagnetic wave of intensity 1400 W m falls on metal surface on area 1 5 m is completely absorbed by it Find out force exerted by beam 1 14 10 5 N 2 14 10 N 3 7 105 N 4 7 10N

27 A force F is applied on the top of a cube as shown in figure The coefficient of friction between the cube and the ground is u If F is gradually increased the cube will topple before sliding if F 1 1

ABC is an equilateral triangle with O as its centre F 1 F 2 and F 3 represent three forces acting along the sides AB BC and AC respectively If the total torque about O is zero then the magnitude of F3 is A F 1 F1 F2 2 2 2 F F 3 F F O F C F

Current flows in a long thin walled cylindrical conductor of radius R uniformly distributed The pressure generated in the wall due to magnetic interaction of attraction type X 4401 47 R H 47 R 14012 87 R

48 A bus starts from rest and travels a distance s along a straight horizontal road The coefficients of static and kinetic friction between the road and the tyres are and respectively The minimum time of travel is proportional to 1 HK 2 1

An open cylindrical container has a cross sectional area Ao 150 cm and water has been filled in it up to a height h A cylinder made of wood relative density 0 6 having cross sectional area A 125 cm and length 10 cm is now placed inside the container with its axis vertical Find the distance x of the base of the wooden cylinder from the base of the container in equilibrium for following three cases a h 8 cm b h 12 cm c h 0 8 cm

7 106 For the arrangement shown in the fig the tension in the string is 107 30 m 1kg M 0 8 1 6 N 2 6 4 N 3 0 4 N 4 Zero The energy required to accelerate a car from 106 4 107 4F 6F 2 7 7 30 1 6 N 3 0 4 N 10 f 3 F

A cylindrical block of weight 314 N is placed on horizontal surface If it exert pressure of 200 Pa on the surface then find the circumference of circular part of cylinder O 2tm KIN m

g of light by the colloidal particles gives rise to Tyndall effect Reason R The colour of the scattered light depends on the size of the scattering particl es A Both A and R are true and R is the correct explanation of A B Both A and R are true and R is not the cor rect explanation of A C A is true but R is false

20 A uniform disc of radius R lies in x y plane with its centre at origin Its moment of inertia about the axis x 2R and y 0 is equal to the moment of inertia about the axis y d and z 0 where d is equal to 17 b Red c 13 R 2 4 a R 3 15 d R 2

placed It may seem that the force between two point charges placed in a medium other than the vacuum changes from what was the force between them in vacuum However this statement is incomplete The correct statement is that the force between two charges placed in a medium other than vacuum does not change from what was the force between them in vacuum but the force experienced by each charge alone in totality changes To understand this statement clearly let us consider the scenario shown in the figure experien F Q F Q F In this figure the yellow particles are the charged particles of the medium Here F is the force on Q due to Q and vice versa and F is the force on the charges by the medium k Q Q Therefore the net force on the charge is F F F

Two conducting large plates P and P2 are placed parallel to each other at very small separation d One side surface area of each plate is A A charge 2Q is given to plate P and Q to the plate P2 If P and P are now connected by conducting wire then total amount of heat produced is 1 3 4Q d 3 A 3Q d AF 2 9Q d 8 A 4 None of these

What is the concentration of O in a fresh water stream in equilibrium with air at 25 C and 1 0 bar Given KH Henry s law constant of O 1 3 x 10 mol kg bar at 25 C A 8 736 x 103 g kg B 4 16 x 102 g kg C 24 04 g kg D 1145 g ke

Figure Q1 b shows the plan view of two concentric cubes The surface area of the inner cube A is 24 cm The side length of outer cubes B is twice the length of cubes A s Point 1 is at the center between cubes A and B The charges at each concentric squares are stated in Figure 1 b The voltage potential at point 2 is 1 5 times higher than the voltage potential at point 1 Calculate the distance between point 1 and point 2 3 nC 1 nC 5 nC 0 B A A 92 15 marks il

27 The position x of a body is given by x A sin wt Find the time at which the displacement is maximum Sol The value of position x will be maximum when th value of sin ot is maximum for this sin wt 1 sin 2 or t T t TC

A particle moves in a circle with constant speed 4 m s The magnitude of change in the velocity when angular displacement of particle is 180 is m s

the magnitude of the negative charge on the particle greater the magnitude of the charge on the particle greater is the interaction with the electric or magnetic field and thus greater is the deflection the mass of the particle lighter the particle greater the deflection