Physics Questions

The space between two large plane surfaces is 2 5 cm and it is filled with glycerine What force is required to drag a very thin plate 1m in area between the surfaces at a spee of 1 m s The plate is at a distance of 1 cm from one of the surfaces n 0 75Ns m ONO 100 N 75 N 50N

1 The angular position of a particle revolving about an axis is given by 0 t t 3t 4 radian Find the acceleration of the particle at time t 2s Given radius of circular path is 1 m 1 2 m s 2 1 m s 3 5 m s 4 5 m s

A parallel plate capacitor having capacitance Co is connected to a battery of emf E It is then disconnected from the battery and a dielectric slab of dielectric constant k completely filling the air gap of the capacitor is inserted in it If AU indicates the change in energy then A AU 0 1 B AU C E K 1 C AU 2 1 C E 1 1 D AU k k

A cylinder of radius R 20 cm is moving between two planks as shown in figure There is no slipping at any point The angular speed of cylinde is 10 m s 20 rad s O 10 rad s 8 rad s O 40 rad s 2 m s phy 08

and B are placed in front of slits A and B respectively If pAtA BtB then the centra maxima may ONO not shift shift towards A if t tB

The energy of a tungsten atom with a vacancy in L small is 11 3KaV Wavelength of K photon for tungsten is 21 3pm If a potential difference of 62kV is applied across the X raystube following characterstic X rays will be produced ONO K L series only ko and L series only L series none of these

3 May be zero 4 All of these Figure shows two containers P and Q with same base area A and each filled upto same height with same liquid Select the correct alternative P P 1 P Py 2 P Py 3 Py P 4 Cannot say Py Q

A conducting wire is bend into a loop as shown in the figure The segment AOB is parabolic given by t equation y 2x while segment BA is a straight line x 2 The magnetic field in the region B 8k tesia and the current in wire is 2A B x in m

The figure shows a Young s double slit experimental setup It is observed that when a thin transparent sheet of thickness t and refractive index u is put in front of one of the slits the central maximum gets shifted by a distance equal to n fringe widths If the wavelength of light used is 7 t will 2019 Main 9 April 1 be

36 In the arrangement shown a and a are the acceleration of the two blocks 1 2 with respect to ground in upward direction and a be the magnitude of relative acceleration of each block with respect to lift Regarding the tension in the string the incorrect statement is m m m 1 4 T 2 m 1 T mg m a 2 T m g m a T m g a 2m m A Lift is accelerating up with acceleration a g a

A rupee coin starting from rest rolls down a distance of 1 m on a plane inclined at an angle of 30 with the horizontal Assuming that g 9 81 ms taken is 1 Correct Answer 3 Your Answer 2 0 32 s 0 48 s 0 782 s 10 s

Note The effective mass of the solid whose energy expression k A B cos k b cos k b near 0 0 is equal to Answer b d Bb 2 Bb Bb You are attempting question 5 out of 12 Bb A B OC OD

Van Der Waals Equation 10 moles of CO gas is taken from an INITIAL STATE 300K 0 1 m to a FINAL STATE 300K 0 2 m Van Der Waals equation is P an V nb nRT m6 mol m mol Where a 0 3643 Pa R 8 314 J mol K and b 4 27 x 10 5 for CO Gas 6 Find the Pressure in the INITIAL STATE denoted by Pia using ideal gas equation 7 Find the Pressure in the INITIAL STATE denoted by Pod Jusing Van Der Waals equation of state 8 Find the value of of relative error in the INITIAL STATE using the formula e pl 11 Find the value of relative error in the FINAL STATE using the formula ef 12 Why is ef less than e vd 9 Find the Pressure in the FINAL STATE denoted by Pi using ideal gas equation 10 Find the Pressure in the FINAL STATE denoted by PJusing Van Der Waals equation of state id id

46 In a series resonant LCR circuit the voltage across R is 100V and R 1KQ2 with C 2 F The resonant frequency is 200 rad s At resonance the voltage across L is 1 2 5 x 10 V 2 40 V 3 250 V 4 4 x 10 V

15 A body of density p is dropped from rest from a height h into a lake of density a where a p Neglecting all dissipative forces the maximum depth to which the body sinks before returning to float on surface e 3 h o p hp 2 hp ho

How long can an electric lamp of 500 W be kept glowing b fusion of 2 kg of deuterium Take the fusion reaction as 2He n 3 27 MeV 2 TH 1H 3 3 15 x 10 1 s 3 15 x 10 4 s min sec 3 15 x 107 s

In RLC circuit at a frequency v the potential difference across each device are AVR max 8 8V AVL max 2 6V and AVC max 7 4V The composed potential difference AVC AVL max across inductor and capacitor is ONO No 10 0 V 7 8 V 7 4V

7 An alternating voltage V Vo sin oot is applied across a circuit As a result a current i io si cot flows in it The power consumed pe cycle is 1 zero 3 0 707 Voio 2 0 5 Voio 4 1 414 Voio

A block of mass m lying on a rough horizontal surface of friction coefficient u is pulled by a force Fas shown the limiting friction between the block and surface will be m AF 30 G

A block mass mis placed on a table which is moving upwith an acceleration a Then the normal reaction acting on the block is 1 mg 2 m g a 3 m g a 4 mg a

A porter lifts a heavy suitcase of mass 80 kg and at the destination lowers it down by a distance of 80 cm with a constant velocity Calculate the workdone by the porter in lowering the suitcase take g 9 8 ms 2 hongo mathongo mathongo mathongo mathongo mathongo 1 62720 0 J 2 627 2 J 3 627 2 J 4 784 0 Jongo mathongo HmathongoH mathongo mathongo mathongo mathongo mathongo mathongo mathongo mathongo mathongo

Two blocks A and B having mass 4 kg and 8 kg respectively are connected by a string If a force of 120N is applied on 8 kg mass The tension between A and B is A 1 20 N T B 120N 2 40 N 3 50 N 4 60 N

A cylindrical conductor of mass m length I and radius r is moving translator with speed u to its length After that a constant uniform magnetic field B is switched on to the plane containing velocity and length The final speed of the cylinder i D u perpendicular perpendicular A zero B C 221 1 26 22 m

1 A particle is moving along x axis Initially the distance of the particle from the origin is a and its velocity is zero The acceleration of the particle at any instant is given by f cosot sinot where t is time Then the maximum distance of the particle from the origin is 1 a 3 a 2 1 2 2 a 4 1 a 2 2 1

long straight solid metal wife of radius 2 mm carries a current uniformly distributed over its circular cross section The magnetic field induction at a distance 2 mm from its axis is B Then the magnetic field induction at distance 3 mm from axis will be Options 2B 3 B 2

A block of mass 10 kg is tied with the help of string rests on an rough inclined plane u 0 5 as shown The frictional force on the block is g 10m s tan 0 9 42 1 50 N 10kg 30 0 9 2 25 3 N 3 100 N 4 Zero

Figure shows a container filled with a liquid of density p Four points A B C and D lie on the diametrically opposite points of a circle as shown Points A and C lie on vertical line and points Band D lie on horizontal line The incorrect statement is PA PB Po Po are absolute pressure at the respective points A petitive Exams Mustpealin

EXERCISE An object of mass m is floating in a liquid of density a If the object is made up of density p then apparent weight of the object in the liquid is 2 mg 1 2 1 mg mal 1 2 4 Zero

A plank of mass M carrying a man of mass m moving horizontally with velocity u on frictionles horizontal surface If the man starts walkir towards right with velocity vo w r t the plank the velocity of centre of mass of plank man is Mu M m 3 u Vo 1 2 Mvo m M 4 u

5 A ray of light falls on a transparent glass slab of refractive index 1 62 If the reflected ray and refracted ray are mutually perpendicular the angle of incidence is 1 tan 1 62 3 tan 1 33 2 tan 4 tan 1 62 1 33

In a young s double slit experiment the slits are illuminated by monochromatic light The entire set up is immersed in pure water Which of the following act cannot restore the original fringe width 1 bringing the slits close together 2 moving the screen away from the slit plane 3 replacing the incident light by that of a longer wavelength 4 introducing a thin transparent slab in front of one of the slits

The pulley is light and smooth Strings are inextensible and light Then tension in the string connecting 2kg and 3kg is g 10m s 2kg 3kg 5kg 1 12 N 2 22 N 3 32 N 4 42 N

A p n junction photodiode is fabricated from a semiconductor with band gap of 2 2 eV It can detect a light of wavelength 6000 nm 5000 700 nm 6000

Q No 19 An object is placed at 20 cm from a convex mirror of focal length 10 cm The image formed by the mirror is 1 2 3 Correct Answer 3 Your Answer 4 Status incorrect Real and at 10 cm from the mirror Virtual and at 10 cm from the mirror Virtual and at 20 3 cm from the mirror Real and at 20 3 cm from the mirror Add to Bookmark List 22 Two massos each of mass Mare attached to the end of a rigid massless rod Right Answer 21 Your Answer 2 Difficulty Lovel low I Topic physics rotational motion Poor Stat Unattemptod 27 8 Correct 63 0 Incorrect 9 2 A rupoc coin starting from rost rolls down a distance of 1 m on a plane in Dienst A

The incident ray reflected ray and the outward drawn normal are denoted by the unit vectors a b and respectively Then choose the correct relation for these vectors mathange mothongo mathongo 1 6 2a 2 6 4 2 ak mathongo mathongo 7 mathongo mathongo mathonga mathong mathong

i A particle is moving with uniform acceleration Its velocity after 48 is 17m s and 7s it is 26m s 1 Initial velocity 2 Velocity after 2s 3 Velocity after 6s 4 Velocity after 10s a 35m s b 11m s c 5m s d 23m s e 26m s a 21 12 7 3 of

A point charge 2Q is placed just inside a cube corner on the body diagonal of the cube If electric flux passing through any of the 7Q KEO adjacent face close to the charge is then value of k is 2Q

and diffraction 1 In interference distance between bright and dark is same but in diffraction width of central maxima is double of other maxima 2 Interference pattern is superposition of two waves originating from two narrow slits diffraction pattern is superposition of a continuous family of waves originating from each point on a single slit 3 For a single slit of width a the first null of the interference pattern occurs at an angle ment is wrong about interference 3 2 a maxima for two narrow slits separated by a distance a Inton of At the same angle of a we get a

The mass of a lift is 2000 kg When the tension in the supporting cable is 30000N then its acceleration is g 10m s 1 30 ms downwards 2 4 ms upwards 3 4 ms2 downwards 4 5 ms2upwards

A small spherical ball is released in a viscous liquid whose density is half that of density of the ball After attaining terminal speed ratio of work done by viscous force to work done by gravity on ball during a certain displacement is Question Type Single Correct Type 1 7 2 3 1 2 2 2

1 A rectangular rigid fixed block has a long horizontal edge A solid homogenous cylinder of radius R is placed horizontally at rest with its length parallel to the edge such that the axis of cylinder and edge of block are in the same vertical plane There is sufficient friction present at the edge so that a very small displacement causes the cylinder to roll off the edge with out slipping If the ratio of translational to rotational kinetic energies of the cylinder when its centre of mass is in horizontal line with the edge is N find N R 157

Find the accelerations of rod A and wedge B in the arrangement shown in Fig 1 20 if the ratio of the mass of the wedge to that of the rod equals n and the friction between all contact surfaces is negligible A a

xo A straight rod of mass m and length L is suspended from the identical springs as shown in figure The spring is stretched a distance due to the weight of the wire The circuit has total resistance R When the magnetic field perpendicular to the plane of paper is switched on springs are observed to extend further by the same distance The magnetic field strength is f 100 www E F ee

3 Two cylinders of same cross section and length L but made of two different materials of densities dy and d are cemented together to form a cylinder of length 2L The combination floats in a liquid of density d with a length L 2 above the surface of the liquid If d d then 3 3x d b d a d 4 b c 0 d d d 4

63 A fish is looking up through the water sees the outside world contained in a circular horizon If water 4 and the fish is 12cm below the 3 and the surface the radius of the circle is 1 36 5 cm 3 36 7 cm 2 4 5 cm 36 4 cm 5

A To minimise the depression in a beam it is designed as T shape girder R The T shape girders have large load bearing surface which decreases the stress

FL Fo 1 Fox Calculate the net work done by the force F whose variation with position has been shown as above 2 3 EIN EI Y X Xo x a hoydle 9345 8 4 All of the above Conservation of mechanical energy can be applied 5 Two identi line A 6 simultanec 50 m s F just after collision 1 20 m 3 15 m Calculate released with ano

54 A man s near point is 0 5m and far point is 3m Power of spectacle lenses required for i reading purposes ii seeing distant objects respectively are 2 2D and 3D 1 2D and 3D 3 2D and 0 33D 4 2D and 0 33D

A body is made of two rods AB and CD rigidly joined together to form a T shape Two springs are attached to this body and the body is free to rotate in a vertical pla about a horizontal axis passing through C as shown in the figure Then the angular frequency in rad s of small oscillation of this system is Mass of each rod is 5 m 6 kg and their lengths are L m Spring constant for each spring is K 96 N m 52 helle K C helle

Two positive charges q are placed on x axis at a 0 and a 0 Variation of electric field along x axis is drawn in graphical form taking electric field to be positive when its direction is along positive x axis Then choose correct graph a 0 a 0 q q x a x a x a O E E E O E x a X x a x a X