Physics Questions

Choose the incorrect statement about areal velocity 1 Direction of areal velocity is perpendicular to velocity and in the direction of radius vector 2 Direction of areal velocity is perpendicular to both velocity and radius vector 3 Direction of areal velocity is in the direction of velocity 4 Direction of areal velocity is in the direction of radius vector

Illustration 27 A galvanometer has a resistance of 30 22 and a current of 2 mA is needed to give a full scale deflection What is the resistance needed and how is it to be connected to convert the galvanometer a into a ammeter of 0 3 A range b into a voltmeter of 0 2 V range

3 The displacement x of a particle varies with time t as x ae at be t where a b a and are positive constants The velocity of the particle will a be independent of B b drop to zero when a B c go on decreasing with time d go on increasing with time 2005

A weightless ladder 20 ft long rests against a frictionless wall at an angle of 60 with the horizontal A 150 pound man is 4 ft from the top of the ladder A horizontal force is needed to prevent it from slipping Choose the correct magnitude from the following a 175 lb b 100 lb d 150 lb c 70 lb

A man of mass 50 kg carries a bag of weight 40 N on his shoulder The force with which the floor pushes up his feet will be 1 882 N 3 90 N 2 530 N 4 600 N

graph of B versus x abruptly 51 Sometimes we show an idealised magnetic field which is uniform in a given region and falls to zero One such field is represented in figure 35 E12 Using Ampere s law over the path PQRS show that such a field is not possible S 10 B Figure 35 E12 S Q R 59

Calculate the molarity of NaOH in the solution prepared by dissolving its 4 g in enough water to form 250 mL of the solution

A sphere of mass m is kept between two inclined walls as shown in the figure If the coefficient of friction between each wall and the sphere is zero then the ratio of normal reaction N N offered by the walls 1 and 2 on the sphere will be A tane B tan20 0 A 1 C 2cos0 D cos20

Example 4 8 Figure 4 15 shows a long straight wire of a circular cross section radius a carrying steady current I The current I is uniformly distributed across this cross section Calculate the magnetic field in the region r a and r a

The two pulley arrangements shown in the figure are identical The mass of the rope is negligible In a the mass m is lifted up by attaching a mass 2m to the other end of the rope In b m is lifted up by pulling the other end of the rope with a constant downward force of 2mg The ratio of accelerations in two cases will be a 1 3 b 1 2 c 1 1 d 1 4 a m 2m b m 2mg

10 The distance between the centres of the earth and the moon is 60 times the radius of the earth Calculate the centripetal acceleration of the moon Acceleration due to gravity on the earth s surface 10 m s Ans 1 360 m s 2 2 1 The mean distance of earth from sun is 1 496 108 km and its sidereal revolution period is 365 3 days The sidereal revolution periods of the planets Venus and Mars are 224 7 days and 687 0 days respectively Estimate the mean distances of these planets from the Ans 1 082 108 km 2 279 x 108 km sun 0

13 Volume of a substance at normal atmospheric pressure is 3500 10 6 m What will be its change in volume at the pressure of 25 standard atmosphere Given that bulk modulus of the substance is 1011 N m 2 85 x 10 9 m

of the 23 The string the spring and the pulley shown in figure 12 E9 are light Find the time period of the mass m p k eeeeee m Figure 12 E9 T mg ma IR kk ft ky za R Solve the previous problem if the pulley has a moment of nertia I about its orig d th MV 29 Find the in figure near the v t B 2gh 9 2 t 0 55

3 A coin is placed on the horizontal surface of a rotating disc The distance of the coin from the axis is Im and coefficient of friction is 0 5 If the disc starts from rest and is given an angular rad sec the number of 1 acceleration 2 revolutions through which the disc turns before the coin slips is 1 4 TC 2 7 4t 3 5 4 4 3 4

A ball is released from the top of a tower of height h metres It takes T sec to reach the ground Bot Instamos a 90x5 TOS 17h D m 18 what is the position of the ball from ground in h A m B 7h m T 13 C second 8h m

Kinetic energy of the system city of centre of mass of two particles is v and the sum of the masses of two particles is m A will be equal to mv C will be greater than or equal to mv Ball 1 B will always be less than 1 mv D will always be greater than mv

Given equation is related to 2 X y cos x cos 2 vt 2 1 Transverse progressive 2 Longitudinal progressive 3 Longitudinal stationary wa 4 Transverse stationary wave

is rele and m m connected by a light spring of natural length is compressed completely and Two masses a quarter of the way tied by a string This system while moving with a velocity v along ve x axis pass through the origin at t 0 At this position the string snaps Position of mass m at time t is given by the equation 0 x t vt A 1 cosot Calculate i Position of the particle m as a function of time ii in terms of A UIT JEE 20031

The speed of a swimmer in still water is 20 m s The speed of river water is 10 m s and is flowing due east If he is standing on the south bank and wishes to cross the river along the shortest path the angle at which he should make his strokes w r t north is given by a 45 west c 0 b 30 west d 60 west NEET 2019

Two identical blocks each of mass m are shown in figure Force exerted by clamp on the pulley is 3 3 mg 4 3 3 mg 4 30 2 3 mg A mg 4

Two particles 1 and 2 are moving with velocities v 41 31 m s and v bi j m s respectively The position vectors of the particles at time t 0 are 51 2 m and 2 41 43 m If they collide at t 3s the value of bis A 10 3 B 5 C 1 D 7

B A A circus performer of weight W is walking along a high wire as shown Assume that wire is very tight Tension in the wire A is approximately W C is much more than W B is much less than W D depends on whether he stands on one foot or two feet constant acceleration

30 Two objects of masses m and 2m are connected by a massless string passing over a fixed smooth pulley The acceleration of heavier mass w r t the lighter mass is 3 8g 3 2 2m 4g 3

Circuit shown is in steady state now when switch is closed galvanometer shows no deflection then correct relation is 1 R C R C 21D C R wwww C C R www C 2 R C R C WRF R c

ass X Three boys A B and C are situated at the vertices of an equilateral triangle of side d at t 0 Each of the boy moves with constant speed v A always moves towards B B towards C and C towards A At what time an where they meet each other troid of the triangle Approaching

7 An iron rod of susceptibility 599 is subjected to a magnetising field of 1200 A m 1 The permeability of the material of the rod is No 4 x 10 7 Tm A 1 2 4mx 10 5 Tm A 1 2 4mx 10 7 Tm A 1 2 3 2 4mx 10 4 Tm A 1 4 8 0 x 10 5 Tm A 1

Wave has simple harmonic motion whose period is 4 seconds while another wave which also possesses simple harmonic motion has its period 3 sec If both are combined then the resultant wave will have the period equal to a 4 sec c 12 sec b 5 sec d 3 sec 1993

The bob of a simple pendulum is replaced by a magnet The oscillation are set along the length of the magnet A copper coil is added so that one pole of the magnet passes in and out of the coil The coil is shortcircuited Then which of the following happens 1 period does not change 2 oscillations are damped 3 amplitude increases 4 period decreases ason

Speed of a boat in standing water is 9kmph and the speed of the stream is 1 5kmph A man rows to a place at a distance of 105km and comes back to the starting point Find the total time taken by him

a 4 b 3 c 2 d 2 Consider a long straight wire of cross sectional area A carrying a current i Let there be n free electrons per unit volume An observer places himself on a trolley moving in the direction opposite to the current with a speed u and separated from the wire by a distance r The magnetic field seen by the observer is very nearly t nAe Ho i Ho i 2 i b zero 2 r Tr Tr a c d

Two wheels having radii in the ratio 1 3 are connected by a common belt If the smaller wheel is accelerated from rest at a rate 1 5 rad s for 10s the angular velocity of bigger wheel will be 1 5 rad s 1 2 15 rad s 1 3 45 rad s 1 4 None of these Current I flows around the wire frame along the

5 In the circuit shown in figure find the amount of heat generated when switch s is closed SV SON

Which one of the following represents a wave a y A sin oot kx b y A cos at bx c c y A sin kx d y A sin of 1994

The diagram shows a solenoid carrying time varying current I It I is constant On the axis of this solenoid a conducting ring is being placed as shown in figure The mutual inductance of the ring and the solenoid is M and self inductance of the ring is L If the resistance of the ring is R then the maximum current which can flow through the ring is A 2M L Io MI B e ring C 2M L Io R D M L Io R

wo sound waves emitted by one sound source is approaching at a point through two path When path difference 3 36 cm or 60 cm then points are silence point if speed of sound in air 330 m sec then find the frequency of sound source bre hoxs inimum tho cliding distance between them

7 Electric current is passing through a solid conductor PQ from P to Q The electric current densities at P and Q are in the ratio Le 2 2 1 4 4 1 1 1 2 3 1 4 2R

A current carrying wire AB with current i is placed as shown in figure Find the magnetic field at origin 6 YA 1 0 01 Molo T 3 0 49 olo TU 0 3 io B 4 0 2 4 0 15 olo TU Holo TC

7 Two balls one of mass m and other of mass 2 m are moving towards each other with respective speeds of 10 m s and 20 m s on a smooth horizontal floor If after collision they stick to each other and move as combined mass perfectly inelastic collision then the speed of combined mass will be NCERT Pg 129 1 20 m s 101 20 m s Ub 2 10 m s 4 50 m s

of earth s magnetic A 255 m wide spaceship moves through the space at a speed 4 5 x 10 m s A magnetic field B 8 x 105T exists in the space in a direction parallel to the plane of motion Treating the spaceship as a conductor calculate the emf induced across its width

4 on The ratio of acceleration of pulley to the acceleration of the block is string is inextensible m F A 0 5 B 2 C 1 Find the velocity of the hanging block if the velocities of the fron figure D None of these

12 Two conducting spheres of radii R and R are kept widely separated from each other What are their individual capacitances If the spheres are connected by a metal wire what will be the capacitance of the combination Think in terms of series parallel connections

8 An airplane pilot wants to fly from city A to city B which is 1000 km due north of city A The speed of the plane in still air is 500 km hr The pilot neglects the effect of the wind and directs his plane due north and 2 hours later find himself 300 km due north east of city B The wind velocity is B 106 km hr at 45 N of E D 106 km hr at 45 N of W A 150 km hr at 45 N of E C 150 km he at 45 N of W aragraph for question nos 39 to 40 An obsencork

Light of wavelength 2 x 10 m falls on a slit of width 4 x 10 m The angular dispersion of central maximum will be a 30 b 60 c 90 d 180

In a screw gauge the graduation in the circular scale consists of 100 equal divisions and 10 complete rotation of the cap is equivalent to 5 mm on the main scale While measuring diameter of a wire with screw gauge a particular observation gives initial circular cap reading as 57 and after completing 3 complete rotation the final circular cap reading as 63 It is observed that while proceeding from initial reading to final reading the cap reading increases Calculate the diameter of the wire from the above data

23 What will be the value of maximum accelera of the truck in the forward direction so that the t kept on the back does not topple 1 ag h 2 hg a 3 ag 2h 4 h bg b h a

COMPREHENSION VIII A thin circular ring of mass m radius R has a uniformly distributed charge Q The ring is placed on a rough horizontal floor The coefficient of friction between the ring and the floor is u A uniform vertically upward magnetic field of radius greater than R and co axial with the ring exists in the space The magnetic field is changing as B Bot2 tesla where t is the time in second where Bo is a positive constant Now answer the following questions based on the above paragraph 26 C Choose the correct graph showing the variation of induced electric field with time t at the circumference of the ring A E B E E D Q M E B

At what height above earth s surface value of g is same as in a mine 100 km deep 292691096 begge 24 01 Corp Reg Office CG Tower A 46 52 IPIA Near City Mall Jhalawar Road An

3 2 i 3j 5k 3 From the top of a tower of height 100m a 10 gm block is dropped freely and a 6gm bullet is fired vertically upwards from the foot of the tower with velocity 100ms simultaneously They collide and stick together The common velocity after collision is g 10ms 2 1 27 5ms 3 40ms 2 150ms 1 4 100ms

A constant force F 20 N acts on a block of mass 2 kg which is connected to two blocks of mas m 1 0 kg and m 2 kg as shown in Fig 3 HT 3 Calculate the accelerations produced in all s three blocks Assume pulleys are frictionless and weightless FIGURE 3 HT 3 F 20N M 2 kg T T o m T m a F4 R FIGURE 3 HT 4 Mg T 2T ta m18 T 192 m2g

A thin wire is bent in the form of a semicircle of radius 1 m as shown in the figure If carries a total charge of 16 2 coul uniformly distributed over its entire length P is a point on the axis of the semi semicircular ring at a distance of 1 m from O Find the component of electric field in volt m along z axis at point P y C P X