Physics Questions

1 250 C 2 600 C 3 Four condensers each of capacity 4m F are connected as shown in the figure If Vp Vo 15 volt the energy store in the system is

21 A solid cylinder is rolling down on an inclined plane of angle 0 The coefficient of static friction between the plane and cylinder is u then condition for the cylinder not to slip is a tan 023 c tan 0 3 A cylinder is rolling b tan 0 3 d tan 0 3

n identical condenser are joined in parallel and are charged to potential V Now they are separated and joined in ser Then the total energy and potential difference of the combination will be 1 Energy and potential difference remain same 2 Energy remains same and potential difference is nV 3 Energy increases n times and potentials differences is nV 4 Energy increases n times and potential difference remains same

Two isolated charged metallic spheres of radii R and R having charges Q and Q respectively are connected to each other then there is 1 No change in the electrical energy of the system 2 An increase in the electrical energy of the system 3 Always a decrease in the electrical energy of the system 4 A decrease in electrical energy of the system until Q R Q R potential of 300 volts Area of the plates is 100 cm and spacing

0 Two identical thin rings each of radius 10 cm carrying charges 10 C and 5 C are coaxially placed at a distance 10 cm apart The work done in moving a charge q from the centre of the first ring to that of the second is a c 9 STEO 9 ATTEO 2 1 2 2 1 2 b d 9 STEO 9 4RE0 2 1 2 2 1 2

148 If a bimetallic strip is heated it will 1 Bend towards the metal with lower linear thermal expansion coefficient 2 Bend towards the metal with higher linear thermal expansion coefficient 3 Not bend at all

The plate separation in a parallel plate condenser is d and plate area is A If it is charged to V volt battery is discon nected then the work done in increasing the plate separation to 2d will be 3 AV d 1 2 2 AV d 2e AV AV 2 d 2d u hottery is disconnected Now the capacitor is connected to 3 4 4

Net force acting on the rod is 1 2qE leftwards 3 Zero 1 2T 3 2 9 m AO me 2qE A light insulating rod AB with two small identical metal balls connected to its ends is placed in a uniform electric field with its length parallel to the electric field Charges on the balls are q and q as shown mass of each ball is m and length of the rod is Assume that the space is gravity free 2ml qE 2 4 2 If the rod is rotated in anticlockwise direction by angle 90 from the position shown torque acting on the rod will be 1 qEl clockwise 2 2qEl anticlockwise 3 qEl anticlockwise 4 2qEl clockwise 38 If the rod is slightly disturbed from the position shown it oscillates with time period 4 FO q m 2 2T Em 2qE rightwards 2qE upwards B me qE E me 4gE

An HCl molecule has rotational vibrational motions If the rms velocity of HCI molecules in its gaseous phase is v m is its mass kg is Boltzmann constant then its temperature will be mv b 3kB a mv 7KB c mv 5kB d mv 6kB April 201

Three charges each of magnitude q are placed at the corner of an equilateral triangle of side a the electrostatic force on each charge w be q q 4 a 3q 4 8 2q 4 e a

Dotted line represents the graph of fnl against t in a charging R C circuit If the resistance of the circuit is doubled which of the following best represents graphs of Enl against time in continuous line B

66 A capacitor of 8 F is connected as shown Charge on the plates of the capacitor a 32 C b 40 C c OC d 80 C 2014 8 F 5 V 20 22 422 12 Karnataka CET

3 Consider a hollow spherical conductor that has a potential of 300 volts at its outside surface The potential inside the hollow space must be a Zero at the center and rising to something less than 300 V at the edge of the hollow space b Zero at the outer part and rising to 300 volts at the center c It depends on the ratio of outer and inner radii d Zero everywhere e 300 V everywhere f 150 V everywhere

1 gram of ice at 0 C is mixed with 1 gram of steam at 100 C At thermal equilibrium the temperature of the mixture is 100 C 55 C 0 C 50 C

There is uniform electric field of 8x10 N C What is the net flux in SI units of the uniform electric field through a cube of side 0 3 m oriented so that its faces are parallel to the coordinate plane 0 3 x 8 x 103 1 2 x 8 x 103 3 Zero 2 4 8 x 106 x 6

1 300 V 2 600 V 3 100 V A capacitor is charged by connecting a battery across its plates It stores energy U Now the battery is disconnected and another identical capacitor is connected across it then the energy stored by both capacitors of the system will be 1 U U F 3 2U 2 allol plate capacitor the distance between the plates is d and potential difference across plates is V Energy stored

In a region of uniform electric field as an electron travels from A to B it slows from UA 6 1 106 m s to ug 4 5 x 106 m s What is its potential change AV VB VA in volts 1 18 3 48 2 18 4 48

Consider two identical rings of mass M and radius R fixed on a horizontal axis in a gravity free space A particle of mass m is held at rest at the centre of 1st ring and projected along the axis towards 2nd ring The minimum speed of projection so that the particle reaches the centre of 2nd ring is M R M R m 14 2R 1st Ring 2nd Ring GM R 2GM V R 1 2 Correct Answer Your Answer 2GM R

39 3 Three identical large metal plates are placed in 39 parallel and surface area of each plate is A then find VA V 2Qd 3 Eo A Qd Eo A 2 2Qd Eo A 4Qd Eo A

The coefficient of volume expansion of a liquid is 49 x 10 5 K 1 Calculate the fractional change in its density when the temperature is raised by 30 C 7 5 x 10 3 0 x 10 2 1 5 10 2 1 1 x 10

View in A constant volume gas thermometer shows pressure reading of 50 cm and 90 cm of mercury at 0 C and 100 C respectively When the pressure reading is 60 cm of mercury the temperature is 25 C 40 C 15 C 12 5 C

Find the speed of transverse waves in this wire at 10 C Given Young modulus of copper 1 3 x 10 N m Coefficient of linear expansion of copper 1 7 x 10 5 C Density of copper 9 10 kg m Sol V V 11 11 HR T SA Stress S yx Strain S yal P yx XAT m L SxA IIT 1979 Sx volume AT 20 C

istration 37 The two conducting spherical shells shown in figure are joined by a conducting wire and disconnected after the charge stops flowing Find out the charges on each sphere after that 2R 8

April 2019 V The specific heats Cp and C of a gas of diatomic molecules A are given in units of J mol K by 29 and 22 respectively Another gas of diatomic molecules B has the corresponding values 30 and 21 If they are treated as ideal gases then a A has a vibrational mode but B has none b A has one vibrational mode and B has two c A is rigid but B has a vibrational mode d Both A and B have a vibrational mode each

Gold crystallises 1 197 N O 3 3 NA in ccp structure The total number of voids present in 197g of gold will be Au 197 4X NAX97 2 2 N 197X 4 4 197 NA relation for r

5 A charge q is placed at the origin O of X Y axes as shown in the figure The work done in taking a charge Q from A to B along the straight line AB is a c 9Q 41E0 92 410 a b ab b 2 a 1 b b d B 0 b A a 0 qQ b a 4TEO ab qQ ATEO a 6

Force of attraction between two point charges Q and Q separated by d meter is Fe When these charges are given to two identical spheres of radius R 0 3 d whose centres are d meter apart the force of attraction between them is 1 Greater than Fe 2 Equal to Fe 3 Less than Fe 4 None of the above

14 The relative velocity of a car A with respect to car B is 30 2 m s due north east The velocity of car B is 20 m s due south The relative velocity of car C with respect to car A is 10 2 m s due north west Find the magnitude and direction of the car C s velocity GollTice SALT LAKE 9874195675 GOLPARK 70440945431 solities gmail com www iitonner com

9 Polarizer and analyzer are set with their polarizing directions parallel so that the intensity of transmitted light is maximum Through what angle should either be turned so that the intensity is reduced to 80 of the maximum intensity 1 Point 30 Degree 26 5 Degree 26 6 Degree 90 Degree

Stress vs strain curve for the elastic tissue of the aorta the large tube vessel carrying blood from the heart will be stress is proportional to square of the strain for the elastic tissue of the aorta

31 In Negative crystal velocity of 1 Point Velocity of O ray is greater than Velocity of E ray in all directions except along optic axis Velocity of 0 ray is less than Velocity of E ray in all directions except along optic axis O ray E ray is equal in all directions except along optic axis

Three rods of the same dimensions have thermal conductivities 3k 2k and k They are arranged as shown with their ends at 100 C 50 C and 0 C The temperature of their junction is 50 C 100 Cr 75 C 200 3 3k 100 LOC 40 C 2k k new in 0 C

17 Two condensers C and C in a circuit are joined as shown in figure The potential of point A is V and that of B is V2 The potential of point D will be 1 2 3 4 A V V V C C V C V C C 2 C V C V C C C V C V 2 D C B 2

Velocity of wave 6 The extension in a string obeying Hooke s law is x The speed of wave in the stretched string is v If the extension in the string is increased to 1 5 x find the new speed of wave V Sol V T E KX u K x u

A charge q is distributed over two concentric hollow conducting spheres of radii a and b b a such that their surface charge densites are equal The potential at their common centre is 1 Zero 3 9 4 E La b 9 q a b 2 A a b ak qa G kaa 0 9 a b 4 4 a b 2

Two charges 2 C and 8 C are placed at two vertices of equilateral triangle of side 1 m The potential at third vertex of the triangle is NCERT Pg 57 1 90 x 103 V 2 9 103 V 3 0 9 103 V 4 900 x 10 V

A three stage amplifier has a first stage voltage gain of 100 second stage voltage gain of 200 and third stage voltage gain of 400 Find the total voltage gain in dB Note answer must have decimal point upto 2 decimal e g if answer is 20 you can write it as 20 00

Two particles of mass M and 2M moving as shown with speeds of 10 m s and 5 m s collide elastically at the origin After the collision they move along the indicated directions with speed v and v are nearly 2019 Main 10 April I M 2M 10 m s 30 45 5m s 30 45 2M M

pov It is cut into two symmetrical halves by a plane containing the principal axis and then two pieces are joined as shown in fig The power of the combination will be P A B A B 1 Zerc

1 kg of gaseous CO2 contained in a closed system undergoes a reversible process at constant pressure During this process 42 kJ internal energy is decreased Determine the work done during the process Take cp 840 J kg C and cv 600 J kg C

A plane progressive wave of frequency 25 Hz amplitude 2 5 x 105 m and initial phase zero propagates along the negative x direction with a velocity of 300 m s At any instant the phase difference between the oscillations at two points 6m apart along the line of propagation is and the corresponding amplitude difference is m IIT 1997C s A6 KAX 2 0x 2 5 6 300x1 25 A is amplitude of all particles travelling Same in a wave

The input power to an amplifier is 15mW while output power is 2W Find the decibel gain of the amplifier Note answer must have decimal point upto 2 decimal e g if answer is 20 you can write it as 20 00

A multistage amplifier employs five stages each of which has a power gain of 30 What is the total gain of the amplifier in db Note Answer must be upto two decimal point eg 20 089 20 09 and don t write dB in answer

13 The condition for minima in Fraunhoffer diffraction for single slit is a sin 8 m A Why m cannot be zero 1 Point For m 0 minima will be formed at the centre of the screen For m 0 diffraction pattern will not be observed at all and screen will be totally bright For m 0 condition for central maxima will be satisfied For m 0 diffraction pattern will not be observed at all and screen will be totally

26 kg block is connected to a 78 78 kg block by a string The blocks are sliding across a surface where the coefficient of kinetic friction is 0 0 0 06 a What is the magnitude of the common acceleration of the blocks m s2 b What is the tension in the string

speed in km s with which it hits the surface of the earth A bullet is fired vertically upwards with velocity v from the surface of a spherical planet When it reaches its maximum height its acceleration due to the planet s gravity is th of its value of the surface of the planet If the escape velocity from the planet is vev N then the value of N is ignore energy loss due to atmosphere 4

26 Obtain an expression for the acceleration of a particle performing circular motion Explain its two components OR For a particle performing uniform circular motion v xr Obtain an expression for the

5 Calculate the minimum thickness of glass plate which appear dark in reflected light for which angle of refraction 60 degree u 1 5 and 5890 AO 1 Point 3 92 10 7m 3 29 10 7m 3 0 10 7m 4 0 10 7m

12 An infinite plane sheet of positive charge has surface charge density o A metallic ball of mass m and charge Q is attached to a thread and is tied to a point A on the sheet PQ The angle e made by the string with the plane sheet is in equilibrium is b tan Qo 48 mg Qo E ma a zero c tan Qo 2 mg d tan

Consider the magnetic circuit of Fig 2 21 a The permanent magnet material Alinco 5 is in demagnetized state It is required to be magnetized to a reduced flux density B 1 25 T Magnetic circuit dimensions are Am Ag 2 5 cm 1m 4 cm lg 0 2 cm Excitation coil turns N 200