Physics Questions

1 A cylinder of length 10 cm made of material of density 0 65 g cm floats half submerged in an ideal liquid kept in closed vessel as shown in the figure Air in the vessel has density 1 30 kg m If pressure of air in the vessel in made 100 times of its initial value what will you observe a The cylinder moves upwards b The cylinder moves downwards c Displacement of the cylinder is 0 56 cm d Displacement of the cylinder is 0 60 cm

In the circuit shown in figure when the input voltage of the base resistance is 10 V V is zero and V is ce also zero Value of is RU B V 0 W 100 k 1636 OU 133 10 V 9 R 3 ks2 O 2 154 C VBE 0 OVUCE

If equation for angular displacement of a particle moving on circular path is given by e 2t 6 where 0 is in radian and t in second then angular velocity of the particle at t 2 seconds is 6 rad s 1 8 rad s 1 12 rad s 1 24 rad s 1

68 An ideal gas follows a law according to that its pressure varies with volume as P 1 V B where a and are constants The temperature of the gas at volume V is equal to No of moles 1 1 3 a 2R a 2R 2 4 a 2R a R 74 75

Which statement is not true 1 Nerve impulse include wave of depolarisation 2 Nerve impulse include wave of repolarisation 3 Synaptic cleft is a gap which is always presen between presynaptic post synaptic neurons

23 The input signal given to a CE amplifier having a 1 voltage gain of 150 is V 2 cos 15t corresponding output signal will be 1 2 cos 15t 5 6 3 TC The I 1 3 300 cos 15t 2 2 300 cos 15t 4 3 4 75 cos 15t 2 3

A particle performs SHM with a period T and ampli tude a The mean velocity of the particle over the time interval during which it travels a distance a 2 from the extreme position is 1 a T 2 2a T 4 a 2T 13a T

f A and are two vectors given by A 21 31 and B 1 1 then magnitude of A B is C 5 5 5

4 The displacement produced by a simple harmonic 10 period and maximum velocity of the particle will be wave is y sin 200nt T 17 respectively 1 10 3 second and 200 m s 2 10 2 second and 2000 m s 3 10 3 second and 330 m s 4 10 4 second and 20 m s X cm The time

resistance Explain which one of the two wires is thicker 2 b If current flowing in a copper wire is allowed to flow through an iron wire of same thickness then explain how drift velocity will change 2 c In a Potentiometer setup experiment on meter bridge AB if the balancing length

61 the circuit shown in figure below the ammeter A reads 1 6 A and ammeter A3 reads 0 4 A If wo is angular frequency and f is frequency of ac then 4 1 0 LC 2 f 2 LC L 88000000 A3 A ac A C 3 The ammeter A reads 1 2 A 4 The ammeter A reads 2 A la tho ac sours

A wave is represented by y 2 sinn 4t x where x and y are in metres and t is in seconds The wavelength of the wave is 01m 1 2 m Read More 02m

2 2 A vessel contains 1 mole of O gas at a temperature T The pressure of the gas is P Ar identical vessel containing 2 mole of He gas at a temperature 2T has a pressure of 1 2P 2 P 3 4Pre 4 8P

Two stones are thrown vertically up simultaneously from the top of a tower of height 200 m with speeds 30 m s and 15 m s at t 0 The time variation of relative position of first stone with respect to the second is a straight line till the time t to seconds Find the value of to

60 If a particle moves in a circle describing equal angle in equal time then its velocity vector Remains constant Changes in magnitude Changes in direction Changes in magnitude and direction min

Which of the following operations is not possible in case of scalars and vectors

23 Volume versus temperature graph for two moles of monoatomic gas is as shown The ratio of work done by the gas to heat absorbed by it in the process A to B is VI 1 3 2 3 7 A B T 2 4 25 352

A man of mass M is on the floor of a lift and lift is moving up with increasing speed with acceleration a then a Normal reaction is more than his true weight b Man appears to be lighter by a g times his true weight O a and b are correct Read More a and b are incorrect O a is correct and b is incorrect

For stationary wave which of the following state ment is correct 1 All the particles vibrate in same phase 2 All the particles between an antinode and node vibrate in phase 3 Particles between any two consecutive nodes vibrate in phase vibrate in different phases

A diatomic ideal gas initially at temperature T is enclosed in a cylinder fitted with a frictionless piston The gas is allowed to expand adiabatically to a temperature T If the lengths of gas column 2 in cylinder are L and L respectively then is T T 1 2 2 5 4 2 3 2 ong 4 5 2 3 2 4 12

In a new system of units unit of mass is 10 kg un length is 1 km and unit of time is 1 minute the value of joule in this new hypothetical system is 1 3 6 104 new units 2 6 107 new units 3 10 1 new units 4 1 67 104 new units

5 Figure shows a block of mass m moving without friction along three tracks with same speed v Normal reaction R R and R relates as m TR TH R R R R R3 2 R R R do D

A frictionless track ABCDE ends in a circular loop of radius R A body slides down the track from point A which is at a height h 5 cm Maximum value of R for the body to successfully complete the loop is B D

The output of the combination of gates shown in figure is A I 3 A A B A B AB Read More A B A B

01 Which of the following is correct 1 It is possible to have dv 0 but dv dt dt 2 It is possible to have 3 It is possible to have X4 All of these dv dt dv dt 0 and d v 0 0 and d v dt d v dt 0 0 ra pra

A mass M attached to a horizontal spring executes S H M of amplitude A When the mass M passes through its mean position then a smaller mass m is placed over is it and both of them move together with amplitude A The ratio of A B M m M D M M m M m C 2 2 M

1500 turns per metre and an iron core of 1100 is kept inside it 2 A current flows in the coil of solenoid If core is heated beyond curie temperature then 1 The H and B fields in the solenoid reduces to zero 2 The H and B fields in the solenoid remains unchanged 3 The H field in the solenoid is nearly unchanged but B field decreases significantly 4 The B field in the solenoid is nearly unchanged but H field decreases significantly

44 Two gases A and B having the same temperature T same pressure P and same volume V are mixed If the mixture is at the same temperature and occupies a volume V the pressure of the mixture is 1 2P Bond P 3 2 2 P 4 4P

A conducting circular loop is placed in a uniform magnetic field of induction B tesla with its plane normal to the field Now the radius of the loop starts shrinking at the rate dr dt r wil Then the induced emf at the instant when the radius is be rB 2 rB 2 Tr dr dt 2 2 dr dt dB dt B dr dt

6 If a capillary is radius r is dipped in water the height of water that rises in it is h and its mass is M If radius is made four times then mass of water that will rise in capillary will be 1 4M 3 M 2 2M 4 M 2

having same cross section and length have been joined as shown The temperature of the junction of four rods will be 10 C 0 20 C 100 C 70 C 1 20 C 2 25 C 3 50 C 4 60 C

Figure shows a block of mass m moving without friction along three tracks with same speed v Normal reaction R R and R relates as TR TD R R R 43 R R R R R 2 R R R R R R

1 Two particles are in SHM on same straight line with amplitude A and 2A and with same angular frequency It is observed that when first particle is at a dis tance A 2 from origin and going toward mean po sition other particle is at extreme position on other side of mean position Find phase difference between the two particles 45 2 90 3 135 4 180

A point particle of mass 0 1 kg is executing S H M of amplitude of 0 1 m When the particle passes through the mean position its kinetic energy is 8 10 J The equation of motion of this particle when the initial phase of oscillation is 45 can be given by 1 0 1 cos 4t 41 5 TU 2 0 1sin 4t 4 4 0 2 sin 3 0 4 sin t TC TU H 4 C 2t

9 A closed container having an ideal gas is heated gradually to increase the temperature by 20 The mean free path will become remain 2 Same 4 33 less 1 20 more 3 20 less

A 54 5 V 3 52 B 3 5 V 54 50 C 11V 2 32 D 3V 5402 A 102 resistor is rated capable of dissipating 5W The maximum current the resistor can tolerate A 0 5A B 0 707A C 1 414A D 1 A A p d of 100V is applied across a copper wire of length 1m The average drift

A cylindrical tube closed at one end has a fundamental frequency f in air The th of the tube is filled with water The fundamental frequency of the air column s now 0 Read More 412

15 60 8 ms 1 The distance x along x axis and height y for a body projected in x y plane are given as x 6t and y 8t 3t The initial speed of projection is x y in meter 14 m s 1 12 ms 1 Mark Tor Review 10 ms 1 59 min

The capacitors are initially uncharged In a certain time the capacitor of capacitance 2uF gets a charge 20 C In that time interval the heat produced in the three riesistoris 2 3 and 6 is H H and H respectively then H H3 H in J is 20 wwww T20V 30 60 1 F 2uF

In a potentiometer circuit two wires of same material of resistivity one of radius of cross section a other of radius of cross section 2a are joined in series They are of length L 2L respectively This combination acts as the potentiometer wire of length 3L The emf of the cell in the primary circuit is e internal resistance is pl 27a This cell is connected to the potentiometer wire by a conducting wire of negligible resistance with positive terminal of the cell connected to one end call it A of longer wire Find the balancing length measured from point A obtained in measurement of emf of cell of emf 2 L OL 2 2L 5

4 Two particles of masses M and 4M are released from a 3 distance 10 metres from each other Find the point of collision from smaller particle 8 metres 2 2 metres 3 5 metres 4 6 metres

A 0 5A B 0 707A C 1 414A D 1 A A p d of 100V is applied across a copper wire of length 1m The average drif velocity of electron is Take n 8 5x10 m a 5 81 x 107 22 m A 4 3x 10 mvs B 43x10 mvs C 0 43 m s D 0 036 m s

A satellite can be in a geostationary orbit around earth at a distance r from the centre If the angular velocity of earth about its axis doubles a satellite can now be in a geostationary orbit around earth if its distance from the center is 0 1 7 2 NI r 2 2 2 r 3 4 4 r 2 1 3

19 The angle of dip is 0 on a given meridian which at an angle 0 with the magnetic meridian If 8 i perpendicular to the first meridian then 8 8 am the angle of dip on another meridian which 02 are related as 1 cot 0 cot 0 cot 0 2 tan 0 tan 0 tan 0 3 tane tan 0 tan 02 1 tanf tong tan A tane

22 For the process A B of an ideal gas of fixed mass the density of gas P A B T 1 Increases 2 Decreases 3 Remains constant A First increases then decreases S 27

2 Two similar nature magnetic poles of strength 16 A m and 64 A m are placed at a distance of 120 cm in air At which point on the line joining the two poles the force on another unit north pole will be zero 1 0 8 m from 64 Am 2 0 8 m from 16 Am 3 0 4 m from 64 Am 4 0 6 from 64 Am

r rotates about its axis 49 A conducting disc of ra with an angular speed w in a uniform magnetic field A resistance R is connected between centre and rim of the disc then B Jo R AH AWWWB C 1 No em f will induce across resistance 2 E m f will induce and A is at high potential 3 Current in resistance will flow from A to B 4 Resistance becomes hot due to Joule s heating 17623456 52

What is the refractive index of material of plano convex lens If radius of curvature of the convex surface is 20 cm and focal length of the lens is 30 cm C w c Read More 5

A ray light of intensity incident on a parallel glass slab at the point A and it undergoes partial reflection and refraction as shown in the figure At each reflection 25 of the incident energy is reflected and the rest is transmitted If the rays AB and A B undergo interference then the ratio Imax Imin is C B A B

c 4xy 2 A force F 21 31 k N is acting on body at a position 7 61 31 2k Calculate the torque about the origin a 31 2 12 k Nm b 91 1 7k Nm c 21 12 k Nm d 31 12 k Nm