Physics Questions

Water rises in a capillary tube to a height h it will rise to a height more than h 1 on the surface of sun 3 at the poles 2 in a lift moving down with an acceleration 4 in a lift moving up with an acceleration surface of water because

Match the value of moment of inertia of structures in List I with corresponding results in List II List l List II P Q R 4 30 2R M R R 22 7 Uniform Rod M Uniform Semicircular Ring Axis is perpendicular to plane of ring Uniform disk of initial mass M from which circular portion of radius R is then removed M I of remaining mass about axis which is perpendicular to plane of plate 1 2 3 8MR2 11 MR2 12 13MR2 8 L

When a steady torque acts on a rotating body rigid the body about fixed axis Gets linear acceleration only Gets an angular acceleration Continues to rotate at steady rate Nong of thong

There is a horizontal film of soap solution On it a thread is placed in the form of a loop The film is pierced inside the loop and the thread becomes a circular loop of radius R If the surface tension of the soap solution be T then the tension in the thread will be 1 nR T 2 RT 3 ART 4 2 RT

4 Red green white The effective area of a black body is 0 1 m and its temperature is 100 K The amount of radiations emitted by min is 1 1 34 cal 2 8 1 cal 3 5 63 cal 4 1 34 J

The wettability of a surface by a liquid depends primarily on 1 surface tension 2 density angle of contact between the surface and the liquid 4 viscosity INEET 201

Three liquids of densities p p2 and p with p p p3 having the same value of surface tension T rise to the same NEET II 2016 height in three identical capillaries The angles of contact 0 0 and 0 obey 1 0 0 0 20 T 3 0 0 0 1 2 0 0 0 0 R 2 TO 4 0 0 0 4cm If the work done is 3 x 104 J the valus

A body of mass M rises to height from earth surface where R is radius of h earth If g be acceleration due to gravity on earth surface increase in gravitational potential energy is O mgR mgR 6 3mgR 5

D Water rises in a vertical capillary tube upto a length of 10 cm If the tube is inclined at 45 the length of water column risen in the tube will be RPMT 2003 1 10 cm 3 5 2 cm 10 2 cm 4 20 cm

A plate of mass M length b and breadth a is initially lying on horizontal floor with length parallel to floor and breadth perpendicular The work done to erect on its breadth is mg mg b a 2 mg Omg a a 21 b a 2

is tied slightly loose to a wire frame as shown in the figure And the frame is dipped into a soap sor taken out The frame is completely covered with the film When the portion A is punctured with a pin the thread Frame 1 becomes convex towards A 3 remains in the initial position A B Thread 2 becomes concave towards A 4 either 1 or 2 depending on size of A w r t B ricer upto 01m If the same experiment is repeated in an

Explain why capacitance should be inversely proportional to the separation between the plates of a capacitor a Capacitance is directly proportional to the electric field which is inversely proportional to the distance between capacitor plates b Capacitance is inversely proportional to the electric field which is inversely proportional to distance between capacitor plates c Capacitance is inversely proportional to the electric field which is directly proportional to the distance between capacitor plates d Capacitance is directly proportional to the electric field which is directly proportional to the distance between pacitor plates

A man pulls a 20 kg mass slowly upwards with the help of light string passing over a frictionless pulley as shown in figure The normal reaction by floor on th feet of man is g 10 m s M 50 kg 20 g mg 750 N 300 N 200 N 600 N

In a vessel equal masses of alcohol sp gravity 0 8 and water are mixed together A capillary tube of radius 1 mm is dipped vertically in it If the mixture rises to a height 5 cm in the capillary tube the surface tension of the mixture is 1 217 9 dyne cm 2 234 18 dyne cm 3 107 9 dyne cm 4 10 79 dyne cm

A homogenous cylinder of mass M and radius R is pulled on a horizontal plane by a horizontal force F acting through its centre of mass Assuming pure rolling angular acceleration of cylinder will be O O 2F 3MR 3F 2MR F 3MR

8 An old pinball game machine starts play with a handle pulled back a distance x to compress a spring with a metal ball at rest on the end When the spring is released the ball is sent forward with a significant speed into the pinball machine For this problem the ball reaches a top speed of 4 5 m s when the spring uncoils If the spring constant is 220 N m and the mass of the metal ball is 82 g determine the distance by which the spring was compressed Express your final answer in centimeters Jual 16 0

After heating two pieces of iron they are taken in dark room One of them appears red and another appears blue then 1 The temp of red piece will be more 3 The temp of both pieces will be same 2 The temp of blue piece will be more 4 Nothing can be said about their temp 10 12 watt cm K Temperature

A 10 cm long wire is placed horizontally on the surface of water and is gently pulled up with a force of 2 10 N to keep the wire in equilibrium The surface tension in Nm of water is 1 0 1 2 0 2 3 0 001 C1 4 0 002 75 om to 10 cm x 6 cm is

A closed cylindrical tube containing some water not entire filled lies in a horizontal plane If tube is rotated about a perpendicular bisector the moment of inertia of water about the axis O Increases Decreases Remains constant Decreases if rotation is clockwise and increases for anticlockwise

Three particles of same mass lie in x y plane The x y co ordinates of their positions are 1 1 2 2 and 3 3 respectively The x y co ordinates of centre of mass are 1 2 2 2 3 0

Potentiometer can be used to measure emf of any cell more effectively than voltmeter because OIt works on deflection method OIt use a large current to measure emf OIt draws no current from cell while measuring its emf OIt is based on Wheatstone bridge

3 10 6 N A proton and an a particle enter a uniform magnetic field perpendicular with the same speed If proton takes 20 s to make 5 revolutions then the periodic time for the a particle would be 1 5 s 2 8 s 3 4 16 s from origin with a velocity voi in a uniform magnetic 10 s

1 A In The spectral emissive power of a black body at a temperature of 6000K is maximum at 5000 A If the is increased by 10 then the decrease in will be temperature 1 2 5 2 5 0 3 7 5 4 10 ission of energy by a unit area of a body is 10 watt and that of sun is 106 watt The emissive power of

Fraunhofer lines are found in 1 Emission spectrum of the elements present in photosphere 2 The absorption spectrum of the elements present in photosphere 3 The emission spectrum of the elements present chromosphere 4 The absorption spectrum of the elements present in chromosphere

The additional kinetic energy to be provided to a satellite of mass M revolving around a planet of mass Mo to transfer it from a circular orbit of radius R to adius R R R is GMOM R R 2 R R GMOM R R 4 R R GMM RZ R 2 R R B R

A conducting wire is bent to form a quarter of circle of radius r and moved in a uniform magnetic field of induction B as shown in the figure The emf induced across the ends of the wire will be X X X X X X X X X M X X X Vo X N X X Answer X X X X X X Rate this question

Two identical calorimeters of negligible heat capacities are filled with two liquids A B whose densities are in the ratio 4 3 The ratio of times taken in cooling from 80 C to 75 C is 5 6 The ratio of their specific heats is 11 2 2 5 6 3 4 3 4 5 8 nives heat from a heated sphere placed at a distance r from it It is found that foil receives

The ratio of masses of two copper spheres of identical surfaces is 8 1 If their temperatures are 2000K and 1000 respectively then the ratio of energies radiated per second by the two is 1 128 1 2 64 1 3 16 1 4 4 1 mom terial and radius with height equal to the radi

1 1 2 2 5 6 3 4 3 4 5 8 Blackened metal foil receives heat from a heated sphere placed at a distance r from it It is found that foil receive power P If the temperature and the distance of the sphere are doubled then the power received by the foil will be 1 P 2 2P 3 8P 4 4P in it takes 4 minutes in cooling from 61 C to 59 C The time tak A L

Diameter of human eye lens is 2 mm What will be the minimum distance between two points to resolve them which are situated at a distance of 50 meter from eye The wavelength of light is 5000 A 2 32 m B 4 28 mm C 1 25 cm D 12 48 cm 11

The acceleration due to gravity on surface of moon is gm The moon is assumed to be sphere of uniform mass density p and radius Rm The density of moon is related to its acceleration due to gravity by relation P 3gm 4 GRm P 4TGRm P 39 m 9m 4x GR min sec 3 GR

A solid body is heated upto very high temperatures As we go on heating its brightness increases and it appears w at the end The sequenc of the colour observed as the temperature of the body increases will be 2 Green yellow red white 1 Yellow green red white 3 Red green yellow white 4 Red yellow green white

wo bodies have their moments of inertia I and 21 respectively about their axes of rotation I Leir kinetic energies of rotation are equal their angular momenta will be in the ratio A 1 2 B 1 2 2 C 2 1 D 1

In millikan oil drop experiment a charged drop fall with a terminal velocity V If an electric field E applied vertically upwards it moves with termina velocity 2V in upward direction If electric fiel reduces to E 2 then its terminal velocity will be V A 2 C 3V B V D 2V

The intensity of heat radiation by a point source measured by a thermopile placed at a distance d is I If the distanc thermopoile is doubled then the intensity of radiation will be 1 I 2 2I 14 3 4 2

1 6000K 2 5500K 3 580 The rate of a cooling of a heated solid sphere is R cal min If it is divided into two hemispheres the rate of cooling at the same temperature will become 1 1 25R cal min 2 1 5R cal min 3 1 75R cal min 4 2 5R cal min liquide A Band of same yolumes are in the ratio 3 2 1 They are allowed to cool in

If an electrical circuit is analogous to a water tank then battery voltage would be comparable to O rate of water flow O O pressure between top and bottom of tank distance to which water flows

4 32 5 C 1 16 5 C 2 22 5 C 3 28 5 C Which of the following surfaces will absorb maximum radiant energy 1 Black 2 Rough 3 Smooth white 4 Rough black incer of iron they are taken in dark room One of them appears red and anothe

The rate of emission of energy by a unit area of a body is 10 watt and that of sun is 10 watt The emissive power the body is 0 1 If the temperature of the sun is 6000K then the temperature of the body will be 4 600 10 K 1 6000K 2 600K 3 600 10 K

Prevost s theory of heat exchange tells that a body radiates thermal energy 1 At temperatures higher than that of surrounding only 2 At temperature lower than that of surroundings only 3 At temperature equal to that of surroundings only 4 At all temperature

A particle moves with a constant velocity parallel to the x axis Its angular momentum with respect to origin Remains constant Goes on increasing Goes on decreasing Constant in magnitude but changes direction mir

4 If Assertion Reason both are false The temperature of a body is increased from 73 C to 327 C Then the ratio of emissive power is AIIMS 2 3 27 4 81 1 1 9 2 1 27 A body initially at 80 C cools to 64 C in 5 min and to 52 C in 10 min The temperature of the surrounding is

Ro The acceleration due to gravity at poles and at equator is go and ge respectively f earth were a sphere of radius Re and rotating about axis with angular speed We then gegp is given by R We Maik T01 Ro 90 90 min sec

Reflection and absorption coefficients of a given surface at 0 C for a fixed wavelength are 0 5 each At the same temperature and wavelength the transmission coefficient of surface will be 1 0 5 2 1 0 3 zero 4 in between zero and one from the centre of the sun to the

cal cm sec C and 0 016 cal cm sec C then the temperature of the junction is 1 40 C 2 60 3 100 C 4 50 C Two rods of copper and brass of same length and area of cross section are joined as shown One end is kept at 100 and the other at 0 C The temperature at the mid point will be

1 500A 2 5000 A 3 50000 A 4 500000 A The rate of cooling of a sphere of thermal capacity 1000 cal K is 400 J s its rate of fall of temperature i 1 0 095 K min 2 0 62 K min 3 2 8 K min 4 5 7 K min

The average translational kinetic energy of one mole of 02 molecules molar mass 32 at a particular temperature is 0 048 eV The internal energy of one mole of N2 molecules molar mass 28 in eV at same temperature is Answer A Your Attempt 0 048 Rate this question Correct answer J

Three rods A B and C of same length and same cross section area are joined as shown in the figure Their thermal conductivities are in the ratio 1 2 1 5 If the open ends of A and C are at 200 C and 18 C respectively the temperature at the junction of A and B in equilibrium is 200 C A K B 2K C 1 5K 18 C 1 156 C 2 116 C 3 74 C In the above question the temperature at the junction of B and C will be 1 134C 2 124 K 3 74 C 4 148 C 4 74 K

Which of the following quantities don t depend on the choice of zero potential O Potential at a point Potential difference between the points O Total potential energy of two charge system Both 2 and 3 are correct

If the radius of sun is R radius of the orbit of earth about the sun is R and ois St radiations falling per second on a unit area of the earth s surface is 1 R OT 2 R R S OT4 3 R TR 4 R R T