Physics Questions

A long wire carrying current I is bent into the shape as shown in the figure The net magnetic field intensity at the centre O is A 1 2 C 4 R B D Hol 4TR 4TR 4 R Hol 4TR 9 O

3 Young s A uniform heavy rope of weight W sectional area A is hanging from rigid support It Young s modulus of material is Y then strain is W 1 4 AY 2 W AY JA

m A given metal wire has length 1m linear density 0 6 and uniform cross sectional area 10 7 m is fixed at both ends The temperature of wire is decreased by 40 C The fundamental frequency of the transverse wave is Y 2x 10 1 coefficient N m of linear expansion of metal is 1 2 x10 C A B C D 0 5 Hz 2 Hz 1 Hz 2 5 Hz

3 Start rotating around earth in a circular orbit 4 Escape from gravitational field of earth Gravitational field intensity 33 A uniform sphere of mass M and radius R is surrounded by a concentric spherical shell of same mass but radius 2R A point mass m is kept at a distance x R in the region bounded by spheres as shown in the figure The net gravitational force on the particle is 1 2 GMm x GMmx R G M m x 3 4 Zero M R m 2R M

A glass sphere of refractive index 1 5 forms the real image of object O at point I as shown in the figure when kept in air of refractive index 1 If the value of x is KR Find k Ho 1 0 X 1 5 C Mo 1 0 R

Region I and II are separated by a spherical surface of radius 25 cm An object is kept in region I at a distance of 40 cm from the surface The distance of the image from the surface is Wmathongo mathongo mathongo mathongo II 25am C 1 25 mathongo mathongo mathongo Amathange 1 4 1 55 44 cm 2 9 52 cm ng mathongo 3 18 23 cm 4 27 5 mathongo mathongo mathongo mathongo mothongo mathonge mathongo mathongo mathongamathongo mathongo mathongo mathongo mathongo mathango mathongs mathongo mathongo mathongo

For observing a cricket match binoculars are preferred to a terrestrial telescope because 1 the binoculars give the proper three dimensions 2 the binoculars have a shorter length 3 the telescope does not give erect image 4 the telescope has chromatic aberration

A square wire loop of side a with a uniformly distributed charge q rotates about its centroidal axis perpendicular to its plane with angular velocity w The magnetic moment of the square wire loop is O qa 3 qa o 6 2 1 379a 0 00

In the circuit shown the switch S is closed at t 0 Then the current through the battery after steady state reached is A 2A B 4A C 6A D 8A 402 www 2 F S 402 ww www 202 5 mH moooooo 602

n number of waves are produced on a string in 0 5 second Now the tension in a string is doubled Keeping radius constant The number of waves produced in 0 5 second for the same harmonic will be n A 2 B C n 2 n

A ring and a disc of different masses are rotating with the same kinetic energy If we apply a retarding torquet on the ring it stops after making n revolutions After how many revolutions will the disc stop if the retarding torque on it is also t A B n C 2 D 2n 4n

For a certain organ pipe three successive resonant frequencies are heard as 300 Hz 420 Hz and 540 Hz If the speed of sound in air is 360 m s then the pipe is a A open pipe of 1 5 m length B open pipe of 3 m length C D closed pipe of 3 m length closed pipe of 1 5 m length

The real angle of dip if a compass needle is kept in a vertical plane at an angle of 30 to the magnetic meridian and in this plane needle makes an angle of 45 with horizontal is 2 O tan tan 1 tan 1 Otan 1 3 2

O No 15 View In English Two sphores A and B have the same radi but the heat capacity of A is greater than that of B The surfaces of both are painted black They are heated to the same temperature and allowed to cool vacuum Then 1 3 4 Correct Answer 4 Your Answer 1 Status incorrect A cools faster than B both A and B cool at the same rate at any temperature the ratio of their rates of cooling is a constant B cools faster than A 4 V

44 Acceleration time graph for an obje motion is shown below a m s 4 8 2 4 10 2 t 10 s till t 18 s 3 t 18 s till t 20 s 18 20 20 m s In which time duration magnitude of change c velocity will be maximum 1 t 0 till t 10 s notion is required t s

0 45 B 2 A long elastic cord obeying Hooke s law is stretched considerably due to its own weight In one such case a cord is held from one of its ends and hung vertically and in another case that is shown in the figure the ends are attached to separate nails A and B in the same level so that the cord assume shape of a catenary In which case is the cord stretched longer

The angular width of the central maxima of the diffraction pattern in a single slit of width a experiment with A as the wavelength of light is 1 2 3 Correct Answer 3 our Answer 2 tatus incorrect 3X 2a 2a 2X a a

c Velocity 2 In the network shown each resistance is equal to R The equivalent resistance between adjacent corners A and Dis a R b R c F 0 V E C N R d R 15 A R m www A 1 boll

45 Position time graph for four objects A D during their motion are shown in figures below In which case the object has constant negative acceleration throughout its motion A C 1 A 3 D t B D O L 2 C 4 B

What is the current through an ideal p n junction diode shown in figure below www 100 2 1 orrect Answer 3 Zero 10 mA 20 mA 50 mA 4 IV

11 The thermal stress developed in the rod by rigid supports as shown F Rigid Support Rod 1 Directly proportional to its length 2 Inversely proportional to its area of cross section 3 Directly proportional to its area of cross section

a 6 31 A particle would take a time t to move down a straight tube from the surface of earth supposed to homogeneous sphere to its centre If gravity were to remain constant then the time would be t The ratio of t t will be be a T a 2 2 b c 2 d TU 4 E L to T 2 2 th satellite of mass m revolves in a circular

A small magnetic dipole is kept at the origin in the x y plane A long wire L is located at z a in the x z plane with a current flowing in the positive x direction Another long wire L is at z a in y z plane with the same current I as in L flowing in the positive y direction The angle 8 made by the magnetic dipole with the positive x axis is 225 120 45 270

When a load of 10 N is hanged from a wire the elongation produced is x mm If the wire goes over a pulley and two weights 10 N each are hung at the two ends the elongation of the wire will be in mm 1 Zero 2 2x 3 X 4 X 0

A flask contains argon and chlorine in the ratio 2 1 by mass at a temperature of 27 C The ratio of molar mass of chlorine to argon is roughly 3 5 The ratio of average translational kinetic energy of argon to chlorine molecule is Options 1 75 7 1 1 41

A particle moves on x axis according to the equation x xo sin wt the motion is simple harmonic 1 2 Correct Answer 4 our Answor 1 with amplitude xo with amplitude 2x0 with time period 2m w with time period m w

To increase the current sensitivity of moving coil galvanometer we should decrease number of turns in coil decrease area of cross section of the coil increase torsional constant of spiral springs None of the above

40 Two coherent planeJight waves of equal amplitude makes a a small angle 1 with each other They fall almost normally on a screen If is the wavelength of light waves the fringe width Ar of interference patterns of the two sets of waves on the screen is 2 b L O A 20 d a

Displace current is given by 1 dE dt 2 3 4 AHO HOEO dE dt Correct Answer 3 Status unattempted dE dt EOA A dE 140 0 dt

A B and C are three rafts floating in a river such that they always form an equilateral triangle A swimmer whose swimming speed is constant swims from A to B then from B to C and finally from C to A along straight lines Time taken by the swimmer is maximum in swimming From A to B From B to C From C to A 03 B River flow It is same in all the parts

21 A telescope has an objective lens of focal length 150 cm and an eyepiece of focal length 5 cm If a 50 m tall tower at a distance of 1 km is observed through this telescope in normal setting the angle formed by the image of the tower is 0 then 0 is close to al bj a 30 b 15 A metal sampl c 84 d 1 2

1 51 The electric field in a region is given E axi Here a is a constant of proper dimensions Find a The total flux passing through a cube bounded by the surface x 1 x 21 y 0 y l z 0 z 1 b The charge contained inside the above cube Ans a al b a 1

For a series LCR circuit given below resonance frequency Then R 12 2 2 and operating angular frequency is half of is the L 6 000 the resonance frequency i e 00 2 R L mm 11 C vo o 1 Power factor of the circuit is 2 Power factor of the circuit is 4 5535 3 Current lags voltage by phase of 53 T 180 37 T

i In the given figure if each capacitor ha capacitance c then the equivalent capacitance between P and Q of the entire circuit is 1 3 2c 7 5c 2 What in th P 2 4 Q 2 2 25 7c

What volume of air measured at 0 C and 1 is needed to burn completely 1 L of butane gas C4H10 measured under the same conditions Assume air has 20 oxygen 1 16 5 L 3 32 5 L 2 3 25 L 4 1 65 L

Figure shows velocity time graph v m s 10 0 10 2 Average velocity for entire journey is 2 5 m s Average acceleration from t 1 to t 4 is 5 m s Average speed for 1st 4 sec is zero 6 Acceleration at t 3 ser is 5 m s t s

What is A x B Is the and gate represented by the multip ly sign also As per we had read it s represented by A B or AB The output X of the logic circuit shown in figure will be A x Be AxB A B A B

7 A rod of length has varying cross section as shown in figure The resistivity of material is p If potential difference across two ends is V then current through the rod is 14 1 3 a V 2p V al 2 4 2 a V pl 3 a V 2p 2a

other end of the string is connected to rigid support passes over a smooth pulley as shown in the figure The horizontal part of the string has length 100 m and oscillates due to formation of standing wave with same frequency as that of bob Mass per unit length of the string is the following questions Q 17 M 100L 100 m Take L 10 m g 10 m s and answer M

DA A straight rod of length L extends from x a to x L a Find the gravitational force it exerts on a poin mass m at x 0 if the linear density of rod A Bx a Gm c A a BL Gm BL A a L 1 4 1 1 b Gm A 1 a a L d Gm BL A a BL

the given circuit initial charge on the ALI capacitor is 1 5 C with polarity as shown in figure and current in the inductor is zero Now at t 0 if the key k is closed then the minimum current through the key is D C 32 3V 222 6 8V 000000Wwwwww 5H k A 33 25 A C 36 25 A 3 80 0 25F A B F HH wwwwww 20 2V B 34 25 A P none

78 Positronium is like a H atom with the proton re by positron a positively charged antiparticle of the electron which is as massive as electron The ground state energy of positronium would be b 5 2 eV a 3 4 eV c 6 8 eV d 10 2 eV energy that must be given to ctron in al to tron

answer Rain is falling vertically with a velocity of 3 kmh A man walks in the rain with a velocity of 4 kmh The rain drops will fall on the man with a velocity of 1 5 kmh 1 3 3 kmh 1 2 4 kmh 1 4 1 kmh 1

A block of mass 5kg released from rest on the top of the smooth inclined plane which is fixed to table as shown in figure It then slides on a rough horizontal surface of 0 2 for 1m It then leaves the top of the table which is 20 0 m high How far from the base of the table does the block lands 1m 5kg fixed 45 H 0 20m 1m 0 2 X

If a particle is moving on a curved path with constant speed then O Velocity remains constant O Body is said to be under acceleration O Body remains unaccelerated Body is moving with decreasing velocity

The following graph shows two isotherms for a fixed mass of an ideal gas The ratio of r m s speed of the molecules at temperatures T and T is H 1 2 2 3 P 2 2 10 Pa N 21 1 I I 2 V m Question Type Single Correct Type 3 4 T

A boy runs on a circular path of radius 14m with a constant speed 4 m s Another boy starts from center of the path to catch the first boy The second boy always remains on the radius connecting the center of circle and the first boy Speed of second boy remains constant 4m s Find the time after which second boy catches first boy Take 22 7

Find the incorrect option for given v t graph 20 A 10 B 10 D 20 30 40 E G 50 60 70 F 1 In AB DE and GH velocity and acceleration have same direction 2 Total distance in ABCDEFG is 600 m 3 acceleration in BC and EF is zero changing its

A car is moving with speed 72 km h on a straight road Suddenly brakes are applied due to which car retards at the rate of 10 m s distance travelled by car before coming to rest is 20 m 200 m O 260 m 190 m

e figue shows an equiconcave lens placed on a plane mirror The focal length of lens in air is 30 cm e refractive index of lens is 1 5 and that of liquid is 2 The combination behaves as A A concave mirror of focal length 15 cm C A concave mirror of focal length 10 cm B A convex mirror of focal length 15 cm D A convex mirror of focal length 20 cm 1000001