Physics Questions

06 The maximum and minimum magnitudes of the resultant of two given vectors are 17 and 7 respectively If these two vectors are at right angles to each other the magnitude of their resultant is A 6 C 11 B 19 D 13

In Young s double slit experiment using a light of wavelength 2 60 fringes are seen on a screen It the wavelength of light is decreased by 50 ther the number of fringes on the same screen will be 1 30 2 60 4 90 3 120

1 In the fusion reaction H H He ont The masses of deutrons helium and neutron expressed in amu are 2 015 3 017 and 1 009 respectively If 1 kg of deuterium undergoes complete fusion Find the amount of total energy release 1 amu 931 MeV C A 6 x 10 3 J C 9 x 10 3 J B 5 6 x 10 3 J D 0 9 x 10 3 J

128 The angle of dip at a place is 60 At this place the total intensity of earth s magnetic field is 0 64 units The horizontal intensity of earth s magnetic field at this place is A 1 28 units B 0 64 units C 0 16 units D 0 32 units

A parallel piate capacitor is filled with two dielectrics as shown in the diagram The area c plates is A and the distance between the plates is d If the thickness of each dielectric slab is d 2 and the dielectric constants are K and K then the net capacitance is K K 2 A K K d K K O BAK K d EoA K K 2d 2 A d

24 A convex a concave lens are brought in close contact along their optical axes The focal length of the convex lens is 10 cm When the system is placed at 40 cm from an object a sharp image of the object is formed on a screen on the other side of the system Determine the optical power of the concave lens if the distance between the object the screen is 1 6 m A 6 7 D C 7 0 D B 6 7 D D 7 0 D

113 The critical angle for total internal reflection of light going from medium I to medium II is given by the relation tan ic 5 9 The refractive index of the I medium with respect to the medium II is A 1 8 C 156 5 B 1 6 D 106 5

103 A nucleus of mass M is at rest An alpha particle of mass m is emitted from the nucleus with momentum P Q value of the nuclear reaction is 1 3 P M 2m M m P M 2m M m 2 4 p m 2m M m p m 2m M m

If a charged particle enters perpendicularly in the uniform magnetic field then 1 Energy remains constant but momentum changes 2 Energy and momentum both remains constant 3 Momentum remains constant but energy changes A Noither one

133 The system shown in figure is just on the verge of slipping The coefficient of static friction between the block and table top is 40 N A 0 5 C 0 15 myy 30 Ow 8 0 W 8 0 N B 0 95 D 0 35

124 A convex a concave lens are brought in close contact along their optical axes The focal length of the convex lens is 10 cm When the system is placed at 40 cm from an object a sharp image of the object is formed on a screen on the other side of the system Determine the optical power of the concave lens if the distance between the object the screen is 1 6 m A 6 7 D C ZOD B 6 7 D D 70D

A uniform rod of mass m and length l is suspended horizontally by the means of two vertical light inextensible strings at the ends c rod Tension in one string immediately after the other string is cut is

Water in a tank is filled to a depth H whose side walls are vertical A hole is made on one of the walls at a depth h below the free surface of water If R is the distance at which the stream strikes the ground then A R 2h H h B R 2 hH C R 2 H H h D R 2 h H h

Rain is falling vertically with a speed of 4 ms After some time wind starts blowing with a speed of 3 mx in the north to south direction In order to protect himself from rain a man standing on the ground should hold his umbrella at an angle 0 given by A 0 tan C 0 cot with the vertical towards south with the vertical towards south B 0 tan D 8 cot www with the vertical towards north with the vertical towards north

Two stones are projected with the same speed but making different angles with the horizontal Their ranges are equal If the angle of projection of one is 3 and its maximum height is Y1 then the maximum height of the other will be A 3y1 C y 2 B 201 D y 3

A current of 5A exists in a 10 resistance for 4 minutes The number of electrons and charge in coulombs passing through any section of the resistor in this time are A 75 x 1020 600C B 75 x 102 600C C 75 x 1020 1200C D 75 x 10 9 1200C

A pendulum of mass m and length is suspended from the ceiling of a trolley which has a constant acceleration a in the horizontal direction as shown in figure Work done by the tension is In the frame of trolley l m a A mg 1 cos0 B mal sine C mal core

A potentiometer wire AB is 100 cm long and has a total resistance of 10 ohm If the galvanometer shows zero deflection at the position C then find the value of unknown resistance R A 40 cm 5V r 122 HEM 10V A 20 C 622 HC R im G B B 42 D 822

What is the capacitance of the capacitor of square plates of area A Shown in figure P K A B Q E A K K 4d K K Eo A K K K 3K K d Eo A K K 3K K K C 4d Eo A d

35 The current through a wire changes with time according to the equation I The correct value of the rms current within the time interval t 2 to t 4s will be A 3 A C 5 A B 3 A D None of these

In a certain double slit experimental arrangement interference fringes of width 1 0 mm each are observed when light of wavelength 5000 is used Keeping the set up unaltered if the source is replaced by another of wavelength 6000 the fringe width will be A 0 5 mm C 1 2 mm B 1 00 mm D 1 5 mm

A black body radiates maximum energy at wavelength A and its emissive power is E Now due to change in temperature of that body it radiates maximum energy at wavelength At that temperature emissive power is A B C 27E 16 81E 16 91E 16

5 The arc AB with the long wire having linear charge density are lying in the same plane The minimum amount of work to be done to move a point charge 90 from point A to B through a circular path AB of radius a is equal to o A 90 2 EO 90 B 20 loge loge 90 C 2 EO 20 D q 2 TEO loge 2 3 2a B a A

A monoatomic gas of presuure P having volume V expands isothermally to a volum 2V and then adiabatically to a volume 16V The final pressure of the gas i 5 ratio of specific heats A B P 16 P 8

A particle of mass 3m is projected from the ground at some angle with horizontal The horizontal range is R At the highest point of its path it breaks into two pieces m and 2m The smaller mass comes to rest and larger mass finally falls at a distance x from the point of projection where x is equal to 3R A 3R 4 B 2 5R 4 C D 3R

A ball is dropped from a height of 20m and rebounds with a velocity which is 3 4th of the velocity with which it hits the ground What is the time interval between the first and second bounces g 10m s2 A 3 sec B 4 sec C 5 sec D 6 sec

130 A block of mass M is allowed to slide down a fixed smooth inclined plane of angle 8 and length What is the power developed by the force of gravity when the block reaches the bottom A 2m gsin0 B 2 3 m3 lg2 sin 0 C 2 3 m t gcos 0 D 1 3 m g 2 sin A

A car is moving with a velocity of 157 7 5 m s and a biker is moving with a velocity of 12 4 5 m s Find the velocity of the car relative to the biker in m s C 3i 12 j D 3i 12 j

A particle is travelling along a straight line OX The distance x in metre of the particle from O at a time t is given by 21 36t 3t where t is time in second The distance of the particle from O when it comes to rest is A 72 m B 69 m C 53 m DY 21 m 11

A point moves along a circle with velocity v at where a 0 5 m sec Then the total acceleration of the point at the moment when it covered 1 10 th of the circle after beginning of motion A 0 5 m sec C 0 7 m sec B 0 6 m sec2 D 0 8 m sec

105 Two waves are represented by Y a cos t kx and y a2 sin ot kx 1 3 Then the phase difference between them is B 7 7 2 A 3 C 5t D 6

17 A charge Q is uniformly distributed over the surface of two concentric conducting spheres of radii R and r R r Such that surface charge densities are same for both spheres Then potential at common centre of these spheres A kQ R r Rr kQ 2 2 C T2 kQ R r B R r 1 D KQ R

08 Temperature of a diatomic gas is 300 K I moment of inertia of its molecules is 8 28 10 38 gm cm root mean square angular velocity is A 10 2 rad s B 10 108 rad s C 1 5 10 2 rad s D 15 x 108 rad s

23 The compound unstable nucleus U often decays in accordance with the following reaction 226 U 140 Xe Sr other particles 92 38 Here the other particles are A An alpha particle B Two protons C One proton and one neutron D Two neutrons

If P is radiation pressure c represents speed of light and Q is radiation energy striking a unit area per second then non zero integers x y and z such that PXQYCZ is dimensionless are A x 1 y 1 z 1 B x 1 y 1 z 1 C x 1 y 1 z 1 D x 1 y 1 z 1

4 A force exerts an impulse I on a particle changing its speed from u to 2u The applied force and the initial velocity are oppositely directed along the same line The work done by the force is 3 A Iu 2 C Iu B Iu D 2 Iu

The electric potential changes from 10 V to 30 V as one moves along x axis from x 0 to x 2 m The magnitude of electric field in the region Must be 10 V m May be 10 V m May be 20 V m Both 2 and 3

A hollow cylinder having infinite length and carrying uniform current per unit length 2 along the circumference shown Magnetic field inside the cylinder is 1 lool A Hod 2 C 2 B D none of these 95 S

Two wheels P and Q are mounted on the same axle The moment of inertia of P is 6 kg m2 and it is rotating at 600 rotations per minute and Q is at rest If the two are joined by means of a clutch then they combined and rotate at 400 rotations per minute The moment of inertia of Q will be A 3 kg m B 4 kg m C 5 kg m D 8 kg m

Which of the following statement is false for a perfect conductor in electrostatic condition The surface of the conductor is an equipotential surface The electric field lines just outside the surface of a conductor is perpendicular to the surface The electric field is continuous across the surface of conductor The electric field is discontinuous across the surface of conductor

The equivalent capacitance of the circuit shown in the figure between terminals A and Bis C C 5 A 05 2C 0 200 5 3C 5 C C B

00 A Carnot engine whose sink is at 300 K has an efficiency of 40 By how much the source temperature should be changed so as to increase the efficiency to 60 A 250K increase B 250 K decrease C 325K increase D 325 K decrease

For measuring potentiometer because voltage of any circuit is preferred to voltmeter The potentiometer is cheap and easy to handle Calibration in the voltmeter is sometimes wrong The potentiometer draws no current during measurement Range of the voltmeter is not as wide as that of the potentiometer

bimetallic strip is made of aluminium and steel aal asteel then on hea e strip will Aluminium Steel ORemain straight Get twisted O Will bend with aluminum on concave side Will bond with otool or novo pido

2 Consider the cyclic process ABCA on a sample of 2 0 mol of an ideal gas as shown in fig The temperature of the gas at A and B are 300K and 500K respectively A total of 1200 J heat is with drawn from the sample in the process Find the work done by the gas in part BC Take R 8 3 J mol K P C A A 3000 J C 4520 J V B B 3000 J D 4500 J 1

Three masses 2 kg 7 kg and 4 kg are connected to each other with threads and are placed on a table as shown in the figure The masses of the pulleys and the threads ar negligible Find the acceleration with which the system is moving in m s 2 kg T A 0 65 m s B 1 54 m s C 3 34 m s 7 kg 4 kg

If n 1 then the dependence of frequency of a photon emitted as a result of transition of electron from nth orbit to n 1 th orbit on n will be A u x C u x 1 n me B u x D u x

The ratio of specific heat at constant pressure to specific heat at constant volume Y for a gas is 1 where f is the number of degrees of freedom of a molecule of a gas The ratio of Ya for rigid diatomic to Ym for monoatomic is A B C D 14 23 25 21 21 25 23

16 An anisotropic material has coefficient of linear thermal expansion a1 a2 and a3 along x y and z axis respectively Coefficient of cubical expansion of its material will be equal to A a az a az B B 2a2 3a3 C 3a1 2a2 az A A 3 D 3

For an isolated uniformly charged spherical Conductor the electrostatic Potential is zero everywhere inside the conductor Field is zero inside the conductor Field is non zero and uniform inside conductor Field is non zero and non uniform inside the conductor