Basic Physics Questions and Answers

A body of mass m strikes a stationary body of mass M and undergoes an elasti collision After collision m has speed one third of its initial speed The ratio m Mis 3 1 02 1 3 2 O 5 3

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

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

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

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

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 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

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

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

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

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

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

A flywheel is rotating about a fixed axis and has kinetic energy of 450 J when it angular speed was 30 rad s1 The moment of inertia of wheel about the fixed axis is O 1 kg m 2 kg m 0 5 kg m 4 kg m

British 1 colour 2 labour 3 traveller 4 counsellor 5 centre 6 theatre 7 organise 8 realise 9 defence 10 offence American color labor traveler counselor center theater organize realize defense offense

Three capacitors each of capacitance C microfarad are connected in series An exactly similar set is connected in parallel to first one The effective capacity of combination becomes 8 F The value of C in microfarad is O 12

The figure shows a system of two concentric spheres of radii r and r and kept at temperature T and T respectively The radial rate of flow of heat in a substance between the two concentric spheres is proportional to 1 r 1 r r 2 In 1 r r 1 4 3 T T 2 512 2 r r 4 r r AIEEE 2005

1 A capacitor having capacitance 1 F with air is filled half half with two dielectrics as shown How many times capacitance will become 1 12 2 6 3 88 4 3

If the termpreature of the sun were to increase from T to 2T and its radius from R to 2R then the ratio of the radi energy received on earth to what it was previously will be 4 ATM AIEEE 201 1 4 2 16 3 32 4 64 The temperature of the two outer surfaces of a composite slab consisting of two materials K and 2K and thickne

m The coefficients of thermal conductivity of copper mercury and glass are respectively K K and K such that K K K If the same quantity of heat is to flow per second per unit area of each and corresponding temperature gradients are X X and X m 1 X X K in 3 X X X m g 2 X X X m 4 X X X m 1 CC The

A 100 eV electron is fired directly towards a large metal plate having surface charge density 2 x 106 C m 2 The distance from where the electron is projected so that just fails to strike the plate is 0 44 mm 0 66 mm O 0 32 mm O 0 16 mm

In the given circuit the sources are ideal and have emf s E 4 V and E2 1 V and the resistance are equal to R 100 R 200 and R3 300 The potential difference VB V across the plates of the capacitor is V MM R 3 R m C AB E R wi I E

View in English A deuteron of kinetic energy 50 keV is describing a circular orbit of radius 0 5 m in plane perpendicular to magnetic field B The kinetic energy of proton that describe a circular orbit of radius 0 5 m in the same plane with the same magnetic field B is O200 keV O 50 keV O100 keV O 25 keV

The coil of a dynamo is rotating in a magnetic field The developed induced emf changes and the number of magnetic lines of force also changes Which of the following conditions is correct que V GR fa emffaf ata a ter tufafa at Affi A Lines of force minimum but induced emf is zero an tani B emf Lines of force maximum but induced emf is zero tag aften f C Lines of force maximum but induced emf is not zero ten af f D Lines of force maximum but induced emf is also maximum ad temi affemf

charge will be same 38 Two plates area s charged to q and 92 9 q are brought closer to form a capacito of capacitance C The potential difference across the plates is 39 1 3 91 92 2C 91 92 For a on 2 4 91 92 C 2 9 92 C

If and u represent the permitivity and permeability of vacuum and and u represent the permitivity and permeability of medium the refractive index of the medium is given by THO A B C D daien Eoflo E E Eotto E V M EO Eo V again a grupal

A spring block system undergoes vertical oscillation above a large horizontal non conducting sheet with uniform positive charge The time period of the oscillation T If the block is given a charge Q its time period of oscillation will be A T C T B T D T if Q is positive and T if Q is negative

If the electric flux through a spherical surface containing some point charges is zero then A the electric field is zero everywhere inside the surface B the electric field is zero everywhere at the surface C the electrostatic potential energy of the system inside the surface is zero D None of these

In the following circuit the output Y for all possible inputs A and B is expressed by the truth table Ao AD Bo A ABY 000 1 0 1 10 1 1 1 1 C AB 00 0 1 1 BY 1 1 1 0 1 1 0 A B ABY 000 B A 0 1 1 D A ABY 010 1 10 0 0 1 0 10 00 1 1 0 1 1 90

Integrated chip IC is an electronic device that contains fa IC A transistors aifGree B resistors afari C transistors and resistors Efter en fari D transistors resistors and capacitors forex gfrieden

A proton a deuteron and an a particle enter a magnetic field perpendicular to the field with same velocity What is the ratio of radii of circular paths 1 2 2 2 1 1 1 1 2

A particle is projected from the gound with an initial speed of v at an agnle 0 with the horizontal The average velocity of the particle between its point of projection and highest point of trajectory is fat a A B C 2 a for a fu 2 1 cos 0 V f 1 2 cos 1 3 cos 0 2 D vcose

A proton moving with velocity v is acted upon by electric field E and magnetic field B The proton will move undeflected with constant speed if 1 E is perpendicular to B 2 E is parallel to v and perpendicular to B 3 E B and v are mutually perpendicular and E y lm w B 4 E and B both parallel to v

A coil of inductive reactance 3192 has a resistance of 8 2 It is placed in series with a condenser of capacity reactance 252 The combination is connected to an a c source of 110 volt The power factor of the circuit is A 0 56 C 0 80 B 0 64 D 0 33

If two conducting slabs of thickness d and d and thermal conductivity K and K are placed together face to face a shown in figure In the steady state temperatures of outer surfaces are 0 and 0 The temperature of common surfac 1 is 1 3 K 0 d K 0 d K d K d K 0 K 0 0 0 2 4 K 0 K 0 K K K 0 d K 0 d K d K d K K

Two satellites S and S revolve round a planet in coplanar circular orbits in the same sense Their periods of revolution are 1 hour and 8 hour respectively The radius of the orbit of S is 10 km When S is closest to S Find the angular speed of S as actually observed by an astronaut S S fem 13 1 f 10 km for starter A 3 10 rad sec B 4x10rad sec C 5 104 rad sec D 6 104 rad sec Your Answer

Maxwell s modified form of Ampere s Circuital Law is weiter au feu a uda 74 642 A B B dA 0 B dA C fEdi dt dos D dog B d f c H Eo dt Your Answer D

In a two dimensional motion of particle the particle moves from point A position vector to point B position vector If the magnitudes of these vectors are respectively r 3 and r 4 and the angles they make with the x axis are 0 75 and 0 15 respectively then find the magnitude of the displacement vector fafanu fars A folus fefa after B foffa f aff A B C D 9 1 18 31 42 75 15 a fazenda 15 13 17 15 2 P

A wall consists of alternating blocks with length d and coefficient of thermal conductivity k and k The cross sectional area of the blocks are the same The equivalent coefficient of thermal conductivity of the wall between left and right is 1 K K 2 K K 2 d K K K K K K 3 K K K K 4 2 K K K K

Try Yourself 6 Resistivity of a conductor of length and area of cross section A is p If its length is dout and area of cross section is halved then its new resistivity will be 1 2 4p 3 P

RADIATION STEFEN S LAW AND WEIN S LAW A metallic sphere having radius 0 08 m and mass m 10kg is heated to a temperature of 227 C and suspended insic a box whose walls are at a temperature of 27 C The maximum rate at which its temperature will fall is Take e 1 Stefan s constant o 5 8 x 10 Wm K and specific heat of the metal s 90 cal kg deg J 4 2 Joule Calorie 1 055 C sec Atalay So the for wha 4 0 03 C sec BC 2 066 C sec 3 044 C sec

Let there be four articles having colours blue red black and white When they are heated together and allowed to cool which article will cool at the earliest RPMT 2007 1 Blue 2 Red 3 Black on of red glass when heated in dark to red hot states will appear to be 4 White Be care of radiation RPMT 20071

XD a 2 c 3 d 4 b A body takes 4 minutes to cool from 100 C to 70 C To cool from 70 C to 40 C it will take room temperature is 15 C 1 7 minutes A verge 2 6 minutes 3 5 minutes 4 4 minutes 80 C to 60 C in one minute The ambient temperature is 30 C In cooling from 60 C to 50

A black body is at room tempreture It is placed in a furnace and it is observed that 1 In begining it is seen most black and later on it is seen most brightest 2 It is always seen black 3 It can t be resolved at any times 4 In begining it is seen most black and later on it can t be resolved

A long solenoid with 1000 turns per meter has a core with a relative permeability of 500 If the current in the windings is 2 A the values of Hand Mare respectively A 8 x10 A m and 9 98 105 A m B 2x10 A m and 9 98 105 A madong 8381 C 2 10 A m and 10 A m D 8 x10 A m and 106 A m 3

The intensity at the maximum in a YDSE is I Distance between two slits is d 52 where is the wavelength of light used in the experiment What will be the intensity in front of one of the slits on the screen placed at a distance D 10d NEET I 2016 4 1 1 1 2 10 JCC 2 3 I

It is hotter at the same distance over the top of a fire than it is on the side of it mainly because 1 heat is rediated upwards 2 Air conducts heat upwards 3 convection takes more heat upwards 4 Conduction convection and radiation all contribute significantly in transferring heat upwards