Physics Questions

When a thin transparent plate of thickness t and refractive index u is placed in the path of one of the two interfering waves of light then the path difference changes by 1 u 1 t 3 1 t 2 1 t 1 4 t WO0034 42 In Young s interferring 1 contrast 2 contras 3 numbe 4 numbe

4 2 cm 1 2 m 9 Two walls of thickness d and d thermal conductivities K and K are in contact In the steady state if the temperatures at the outer surfaces are T and T the temperature at the common wall will be 1 3 K T K T d d K d K d T T T T 2 K T d K T d K d K d 4 Kd T K d T K d K d 35 H F 36 S

A screen is placed 90 cm away from an object An image of the object is formed on the screen by the same convex lens placed at two different locations separated by 30 cm The focal length of the lens is A 15 cm B 20 cm C 25 cm

Pre Medical Physics 43 Many of the diagrams given in figure s magnetic field lines thick lines in the fig Point out which one is are correct A B O C D UUU a

company will receive the maximum monthly income A projectile is launched from a point 40 feet above the ground The height at ground level h in feet after t seconds is given by the function g t 40t 5t2 Find the maximum height of the projectile and the number of seconds will it take to reach the maximum height

If magnetic field is perpendicular then force will act on pa rticle then how will the kinetic energy be constant A charged particle enters in a magnetic field in a direction perpendicular to the magnetic field Which of the following graphs show the correct variation of kinetic energy of the particle with time t

A rectangular sheet of copper is 2 00 mm thick and has surface dimensions 8 0 cm x 24 cm If th long edges are joined to form a tube 24 cm in length find the resistance of the tube in micro ohm between the ends of the tube Resistivity of copper 1 6 x 10 22 m

A person of mass M is sitting on a swing of length L and swinging with an angular amplitude 0 If the person stands up when the swing passes through its lowest point the work done by him assuming that his centre of mass moves by a distance L is close to A Mgl B Mgl 1 0 C Mall1 8 YOU MARKED

27 A 100 W sodium street lamp emits yellow light of wavelength 0 6 m If it converts 40 of electrical energy into light then the number of photons of yellow light it emits per second is 1 1 2 x 1019 2 2 2 x 1019 3 1 2 x 1020 AY 20

On heating a uniform metallic cylinder length increases by 3 The area of cross section of its base will increase by 1 1 5 3 9 2 3 4 6

A fixed sphere of radius R and charge Q uniformly has a small groove of length as shown in figure Another point charge of mass m and charge q is projected towards the groove with some 1 xQq velocity in given direction If maximum value of v so that it does not strike to sphere is 8VmRo then find x Neglect gravity Both charges are of same nature

A rocket of initial mass 6000 kg ejects gases at a constant rate of 16 kg s with constant relative speed of 11 km s What is acceleration of rocket one minute after the blast Neglect effect of gravity 1 25 m s 3 10 m s 2 50 m s 4 35 m s

charge d 4F towards charge A cylinder of radius R and length L is placed in a uniform electric field E parallel to the cylinder axis The total flux for the surface of the cylinder is given by a 2 R E c TR TR b Nab Zero

A student measured the diameter of a small steel ball using a screw gauge of least count 0 001 cm The main scale reading is 4 mm and that of circular scale is 25 If the screw gauge has zero error of 0 004 cm the correct diameter is 1 0 043 cm 2 0 429 cm 3 0 421 cm 4 0 425 cm

Thermal Properties of Matter 261 22 100 g of ice latent heat 80 cal g at 0 C is mixed with 100 g of water specific heat 1 cal 1 C 1 at 80 C The final temp

etic field vectors present at a point P are given by B B and B respectively as shown in the given figure The magnitude of net magnetic field at point P will be B 5 2 T P 45 1 10 10 2 T 3 20 T B 10 T B 5 2 T 2 10 T 4 10 5 2 T

If the tension in the cable supporting an elevator is equal to the weight of the elevator the elevator ma A going up with increasing speedID B going down with increasing speeding C going up with uniform speed D going down with uniform speed

Find average frequency of collision for oxygen molecule of temperature 300 K and pressure 1 atm Average speed for oxygen molecule is 450 m s and molecular diameter is 2 9 10 10 m A B C D 0 41 x 10 sec 4 1 x 10 0 sec 4 1 x 10 sec 4 1 x 10 sec Correct Answer

The system as shown in the figure is released from rest The pulley spring and string are ideal friction is absent everywhere The speed of 5 kg block when 2 kg block leaves the contact with ground is spring constant k 40 N m g 10 m s wwwwwww 3 0 AxPm s B 2 2m s 5 kg 2 kg T C 2 m s 1 50 D 4 2m s

If external magnetic intensity on a paramagnetic material is made 4 times and the absolute temperature is made 3 times then how many times will be the self magnetisation 1 4 times 3 times 3 2 4 1 3 3 4 times times 30 fall and an 1 4 T 3 a fond 4 A m 3 THI

Sir Ma am in Pascal s law it is being told that pressure app lied at any place in an enclosed fluid is transmitted with u ndiminished magnitude to every portions of fluid and acts normally to surface in contact with it Sir Ma am now my question is that what will be the proble m if the fluid is not enclosed

12 Relative permeability of iron is 5500 then its 12 magnetic susceptibility is 2 5501 4 zero 1 5500 3 5499 gracht 1 55 3 5

If the wire is gently tapped in vertical direction halfway between the pulleys what is the lowest frequency at which it will vibrate transversely The mass per unit length of the eire is 0 02 kg m and it has a length of0 2 m between pulleys Volume of block is 1 4 200 3 m and its mass is 10kg Water

ratio of diameters of an air bubble at the bottom and at the surface of a lake is 1 2 What is the depth of the lake 1 atmospheric pressure 10 m depth of water 1 70 m 2 60 m 3 80 m 4 35 m A glass tube 80cm long and open at hath h depth A S

55 Identify the wrong statement regarding the earth s magnetism a b c d the declination is smaller at higher latitudes and greater near the equator In most of the northern hemisphere the north pole of the dip needle tilts downwards If the needle is only capable of moving in horizontal plane it can point along any direction near the poles of the earth The angle of dip at a place on the earth gives the direction of earth s magnetic field 1

a moving coil galvanometer the coil having N turns and area of cross section A is placed in magnetic field B When current I is passed through it the deflection D on the scale by a pointer attached to the spring of torsion constant k is NA kB I a Y NAB AB k b N KAB NAB I

25 A simple pendulum of period Thas a metal bob which is negatively charged If it is allowed to oscillate above a positively charged metal plate its period will a remains equal to T b less than T c greater than T s d infinite

Doesn t a glass slab just shifts the image laterally Then h ow will the distance change Please clear my specific dou bt Plane glass slab is kept between a model and a plane mirror The mirror is 50 cm away from the model The glass slab has a thickness of 15 cm and refractive index of 1 5 At what distance in cm from herself will the model see her image 40 50 80

A sample of gas in a box is at pressure P and temperature To If number of molecules is doubled and total kinetic energy of the gas is kept constant then final temperature and pressure will be 1 To Po 2 T 2P 2 2 12 13

When a dip magnetic needle is suspended in 18 the earth s magnetic field 1 In northern hemisphere the north pole of dip tilts downwards At southern hemisphere south pole of dip tilts downwards 2 In northern hemisphere the south pole of dip tilts downwards At southern hemisphere north pole of dip tilts downwards 3 In both northern and southern hemisphere north pole of dip tilts downwards 4 In both northern hemisphere and southern hemisphere south pole of dip tilts downwards

Consider mass of Sun and Earth to be 2 1030 kg and 6 1024 kg respectively The distance between Earth and Sun is 1 5 10 1 m Calculate the center of gravity of Sun Earth system 450 km from the center of Sun 450 km from the center of Earth 450 000 km inside the Sun 450 km inside the Earth

Consider two coils of radii r and r placed at a distance d away as shown in the figure Assuming the length of the coils 1 1 d with n n the 1 2 number of turns per unit length of the two coils respectively the mutual inductance of the two coils is 4 00000 00000

Mark the CORRECT option A vertical plane containing the vertical axis orthogonal to ground and the longitude is called the geographic meridian O Geographic meridian and magnetic meridian for earth are always same at a point The dip circle is simply a compass needle pivoted about a fixed vertical axis and free to move in a horizontal plane O There is a bar magnet buried deep inside earth s interior which gives rise to earth s magnetic field

An electromagnetic wave is represented by the electric field E Ensin oot 6y 8z Taking unit vectors in x y and z directions to be i j k the direction of propagation is S A B C D S 3j 4k 5 31 4 5 4k 3j 5 4j 3k 5 4 YOU MARKED

A solenoid has core of material with relative permeability 400 The winding of the solenoid are insulated from the core and carry a current of 2A It has 1000 turns meter Then magnetising current will be 1 798 A 2 1000 A 3 500 A 4 1494 A 28 uchufelfeen a 400 T 2A his fayd 1 798 A 3 500 A RE for 41

12 The apparent coefficient of expansion of a liquid when heated in a brass vessel is X and when heated in a tin vessel is Y If a is the coefficient of linear expansion for brass the coefficient of linear expansion of tin is 1 X Y 3a 3 2 X 3a Y 3 X Y 2c 3 13 The coefficient of volume expansion of glycerin is X Y 20 2

A long solenoid has 1000 turns per meter and carries a current of 1A It has a soft iron core of H 1000 The core is heated beyond the critical temperature T 1 The H field in the solenoid is decreases drastically but the B field is nearly unchanged 2 The H and B fields in the solenoid are nearly unchanged 39 3 The magnetisation in the core reverse direction 4 The magnetisation in the core diminishes by a factor of about 108 Test Tafect fenferent 14 A RT 1 f 2 34fafda 3 4 4 affect Grat

rotating Three wire loops and an observer are positioned as shown in the figure From the observer s point of view a current I flows counterclockwise in the middle loop which is moving towards the observer with a velocity v Loops A and B are stationary This same observer would notice that B ooo 1 clockwise currents are induced in loops A and B 2 counterclockwise currents are induced in loops A and B 3 a clockwise current is induced in loop A but a counterclockwise current is induced in loop B 4 a counterclockwise current is induced in loop A but a clockwise current in

9 If in winter season the surface temperature of lak is 1 C the temperature at the bottom of lake will b 1 1 C 2 0 C 3 4 C

A charged particle having mass m charge q is moving with velocity v ai in a magnetic field B pi aj and experiences a force F Which one of the following statement s is are correct 0 0 F 0 for a B Fa B for a B F acts along z axis for a B

No 24 The magnetic field Band the magnetic intensity H in a material are found to be 0 3 T and 400 A m respectively Calculate the relative permeability p and the susceptibility x of the material

1 The magnetic moment produced in a substance of 1 gm is 6 x 107 Axm If its density is 5gm cm then the intensity of magnetisation in A m will be 1 8 3 x 106 3 1 2 x 10 7 2 3 0 4 3 x 10 6

7 A uniform magnetic field B exists in circular region of radius R as shown which is decreasing with time at a constant rate There is a concentric wooden ring which have uniformly distributed charge Q and radius 2R and another concentric uncharged copper ring of radius 3R then select INCORRECT alternative Assume rings are placed on frictionless surface 3R R 2R 1 There is no induced current in wooden ring 2 Induced electric field in wooden ring is more in magnitude than copper ring 3 Induced electric field in copper ring is more in magnitude than wooden ring

A particle of unit mass undergoes one dimensional motion such that its velocity varies according to v x Bx where and n are constants and x is the positi of the particle The acceleration of the particle as a function of x is given by a 28 x 2n 1 b 2n x 4n 1 C 2n x 2n 1 2n82y 4n 1 2n 1

In an isothermal process two moles of an ideal gas expands from volume 2 m to 8 m at temperature of 227 C Heat absorbed by the gas during process is nearly 1 2752 cal 3 1945 cal NCERT Pg 311 1 2 3250 cal 4 1875 cal

A metal rod of mass m can slide without friction along two parallel horizontal tracks connected by resistor R A vertical magnetic field B exists in the region The rod is given initial speed v by a quick push What distance x will it cover before stopping The distance between the tracks is l mvR B 1 2mvR

A transformer operates at V 6 kV on the primary side and supplies electric energy at Vs 220 V to a number of houses in a town If the total power consumption of the town is 7 2 kW the current in amperes in the primary is A 2 B 1 2 C 2 5 D 3 E 1

9 An ideal gas is compressed to half of its initial volume by means of different thermodynamic processes Which of the process result in the maximum work done on the gas NCERT Pg 312 1 Isothermal 2 Adiabatic 3 Isobaric Isochoric 2

A sound wave given by Ap Apo sinw t r v is produced at z 0 and the reflected wat from other end of the closed tube produces standing wave What is the equation of the stand wave produced A Apr 2Apo cos wt sin Apr 2Apo sin ut cos C B Apr Apo sin ut cos D Apr Apo coswt sin

ng y axis an ideal graph is meter of the hole 11 A seconds pendulum clock has a steel wire The clock shows correct time at 25 C How much time does the clock lose or gain in one week when the temperature is increased to 35 C steel 1 2 x 10 5 C 1 321 5 s 2 3 828 s 3 82 35 s 4 36 28 s 12 The apparent coefficient of expansion of a liquid