Physics Questions

9 A river 4 0 miles wide is flowing at the rate of 2 miles hr The minimum time taken by a boat to cross the river with a speed v 4 miles hr in still water is approximately 1 1 hr and 0 minute 2 2 hr and 7 minutes 3 1 hr and 12 minutes 4 2 hr and 25 minutes

3 Current falls to zero after time t 2b 4 Current changes at a rate 2b The current in a conductor varies with time t as 43 I 2t 3t A where I is amperes and t in seconds Electric charge flowing through a section of the conductor during t 2 s to t 3 s is 1 10 C 2 24 C 3 33 C 4 44 C 3 4 2b T 2bafd 1 10 C ac Gai 1 p I ved 2 24 C PRAI 3 33 C 2 3t f 21 3 t 4 44 C

4 In the diagram shown there are four forces acting on a block of mass 2 kg in space The acceleration of the block is 3m s in the direction as indicated Find the unknown force F 10 N ON a3m s 2 kg AN

A solid cylinder attached to horizontal massless spring can roll without slipping along horizontal surface Find time period of oscillation 1 M R G Question Type Single Correct Type 2 2 1 M 2k K wwwwww 3M TV 2k

1 20 A car C travelling at a uniform speed of 75 kph passed another car C at rest beside the track Two minutes later C starts and accelerates uniformly until its speed increases to 100 kph then it maintains the speed After 12 minutes from the instant C passes C C is 800 m ahead of C Find when and where C overtakes C and the acceleration of C Ans 10 1 min 12 6 km 0 443 m s

4 The drift speed varies randomly On increasing the temperature of a conductor its 4 resistance increase because 1 Relaxation time decreases 2 Mass of the electrons increases 3 Electron density decreases 4 None of these 4 kaf Rifer 1 fenfeased and 2 4 questione

A particle of mass 100 g charge C is placed on the vertical axis of a uniformly charged ring of radius 1m This particle is executing S H M of small amplitude with time period 2 s above the centre of the ring a shown in figure Then find the total charge in mC on the ring Take n 10 m In

A string of mass per unit length is clamped at both ends such that one end of the string is at x 0 and the other end at x L When string vibrates in fundamental mode amplitude of the midpoint of string is a and tension in string is F Find the total oscillation energy in J stored in the string Use L 1m F 1 10 N a m 77 x 0 Question Type Numerical Type x L

A galvanometer of resistance 1500 shows full scale deflec tion for a current of 20 mA What is the resistance that should be connected in series with it to get a voltmeter of range 0 30 V 1350

flat firing range Part C Part A Determine the maximum height reached by the projectile VAX 89 4 Submit Previous Answers Request Answer X Incorrect Try Again 2 attempts remaining Part B Determine the total time in the air VAE t 8 54 Submit Previous Answers Request Answer X Incorrect Try Again 4 attempts remaining Determine the total horizontal distance covered that is the range m

QNO 135 View In English An astronomical telescope has objective and eyepiece of focal lengths 40 cm and 4 cm respectively To view an object 200 cm away from the objective the lenses must be separated b distance 0 4 Correct Answer 4 Status unattempted 373 cm 46 0 cm 50 0 cm 54 0 cm

R A solid sphere of radius R gravitationally attracts a particle placed at 3R from its centre with a force F Now a spherical cavity of radius 2 made in the sphere as shown in figure and the force becomes F The value of F F2 is A 36 25 B 41 50 of 3 B 2R m

1 35 C 2 40 C 3 45 C 4 None of these The current through a wire depends on time as 45 i i at where i 10A a 4 A S Then the charge crossed through a section of the wire in 10 sec is 1 100 C 3 300 C 2 500 C 4 None Telegram 1 35 C 3 45 C fa frufe B i i at a 1 100 C 3 300 C 2 40 C 4 i 10A a 4 A S a 10 g m m 2 500 C 4

V k V k 7 0 33 where k is constant It is an 1 Isothermal process 2 Adiabatic process Isochoric process 4 Isobaric process e Leader e Achiever MAZC D E F G H I J K L M MLE F G H I J K MAS

9 A bar of mass m is pulled by means of a thread up an inclined plane forming an angle a with the horizontal Fig 1 13 The coef ficient of friction is equal to k Find the angle which the must form with the inclined plane for the tension of the thread to be minimum What is it equal to thread ohit Go Ta Fig 1 13

For shown situation if collision between block A B is perfectly elastic then find the maximum energy stored in spring in joules B C 3kg 000000 6kg A 3kg 2m s 1 6J 2 8 J 6 4J Smooth 4 10 J e Leader e Achiever MAZC D E F G H I J K L M MLE F G H I J K MO E H 19052021

The absolute coefficient of expansion of liquid is 7 times that the volume coefficient of expansion of the vessel then the ratio of absolute and apparent expansions of the liquid is 1 www g 3 4 1

A body weights 49N on a spring balance at the north pole What will be its weight recorded on the same weighing machine if it is shifted to the equator Use g A B 49 N GM 9 8 ms 2 and radius of earth R 6400 km R 49 83 N

A solenoid of length 0 4 m and having 500 turns of wire carries a current of 3 amp A thin coil having 10 turns of wire and of radius 0 01 m carries a current of 0 4 amp Calculate the torque required to hold the coll in the middle of the solenoid with its axis perpendicular to the axis of solenoid 10 8 10 10 N M 2 6 10 10 N M 3 4 Correct Answer 3 Status unattemptod 6 10 N M 8x10 12 N M

35 On a fixed inclined plane two conducting rails are fixed A conducting rod of length L is placed on the two rails as shown in the figure 1 The conducting rod has mass m and it can slide on the rails without friction There exists a uniform magnetic field B vertically upward in the region At an instant the conducting rod is released from rest The terminal velocity of the rod will be 2 4 mgR cose BL sin e mgR sine B3L mgr sine BL cos e R mgR BL sin e Bo

No 2 View In English A particle moves in the east direction with 15 m sec for 2 sec then northwards with 5 m s for 8 sec Average speed of the particle is 1 1 m s 5 m s 7 m s 10 m s 3 4 Correct Answer 3 Your Answer 2 Status incorrect

10 Prism 1 of mass m and with angle a see Fig 1 23 rests on a horizontal surface Bar 2 of mass m is placed on the prism Assum ing the friction to be negligible find the acceleration of the prism

Two tennis balls of mass 60gm are attached with a massless rubber thread and held in the vertical position as shown in the figure In this position length of the rubber thread is 40cm and it is unstretched The upper ball is showly raised vertically upward until the lower ball just becomes unsupported by the ground At this time the length of the thread is 1m The rubber thread exerts and force which is proportional to its extension What is the force constant of the rubber thread A 2N m B IN m C 0 5 N m How much work is done by external agent while the upper ball was raised A 0 54 J B 0 36 J C 0 18J D 0 25 N m D 0 45 J If we release the upper ball at this position at what speed will it hit the lower one A 4m s B 18 m s C 30 m s D 26 m s

58 A sphere of mass 2 kg is dropped from a height of 0 4 m onto a spring having force constant 1960 N m then maximum compression of spring will be g 9 8 m s 1 0 1 m 3 0 2 m 2 0 15 m 4 0 25 m

The potential difference between points A and B is 2V 192 42 4V 192 1 2 3 3V 192 B 2V 6 V OV 3V

The time period of mass M when displaced from its equilibrium position and then released for the system as shown in figure is 1 2 3 4 Correct Answer 3 2T 21 MERME 2k 24K 2M 21 k Inextensible string 00000000 pulley M

A rear wheel drive car moves with a constant speed v 20 m s on a circular path of radius r 200 m on a horizontal ground Centre of gravity of the car is close to the ground and equidistant from all the four wheels that have negligible mass as compared to rest of the car a What should the minimum coefficient of friction between the tyres and the ground be to make this movement of the car possible

3 64 10 4 32 10 1 A conducting sphere of radius a is enclosed by a 21 conducting shell whose radius of inner surface is 2a and that of outer surface is 3a Charge given to conducting shell and conducting sphere are Q and Q respectively then what will be potential at centre of conducting sphere 3 KQ 2a Nm and Nm and 64 104 J 2KQ 3a 3a KQ 2a KQ 3a 3 64 10 Nm R 32 4 32 x 10 Nm 3 stafar from 2a a ST Telegram ne questionpaper C 3 Q far a fava KQ 2a 2KQ 3a 64 10 J me from 3a are s 3a a 4 KQ KQ 3a

Water from a pipe is coming at a rate of 100 liters per minute If the radius of the pipe is 5 cm the Reynolds number for the flow is of the order of density of water 1000 kg m coefficient of viscosity of water 1 mPa s 1 10 2 104 3 10 4 106

A power P is required in maintaining the liquid flow through a pipe at velocity v If the speed of flow is doubled the new power required will be 1 8P 2 4P 3 2P 4 P 100 5

Electric potential is given by MER 36 faya fara fact ar faen ent V 6x 8xy 8y 6yz 4z 2nd V 6x 8xy 8y 6yz 4z Then magnitude of electric force acting on 2C point charge placed on origin will be 1 2 N 2 6 N 3 8 N 4 20 N A current of 3 2 mA is flowing through a 37 Telegram ne a after 1 2 N 3 8 N 2 6 N 4 20 N 3 2 muna safata fr

The terminal potential difference of a galvanometer is 1 V for its full scale deflection A resistance of 950 con nected in series with it converts it to a voltmeter that can read a maximum of 20 V What is the resistance of the gal 502 vanometer

A helium balloon is released from the atrium floor of Willamette Hall and accelerates upwards at 2 5 m s 2 Air resistance is not a factor How long would it take the balloon to reach the stars on the sculpture 12m above O 2 5s 3 1s O 0 82s O 1 7s

24 If we have an irregularly shaped conductor as 24 ares fanger f shown and a charge is given to it choose the correct statement 5 P 1 the electric field and electric potential at P is maximum among all points of conductor 2 the electric field at P is maximum and electric potential is same at all points of conductor 3 the electric field and electric potential at P is same at all points of conductor P 1 Aga v ga fava en fait m 2 P fargt fa 3 aga va agafava are un fargent 4 the electric field and electric potentiam nequestionpaper at P is minimum among all points of conductor If an electron moves in the direction of electric 25 afe caga faga in sem f 4 aga agafava affari

7 42 A tank is filled with a liquid upto a height H A small hole is made at the bottom of this tank Let t be the time taken to empty first half of the tank and t the time taken to empty rest 4 half of the tank Then find 1

There are two identical square metallic plates kept on a rough horizontal floor at t 0 plates are given angular velocity and it is given that plate 1 is rotating about its centre A and plate 2 is rotating about one of its corner O If t and t are the time taken by both the plates to come to rest then is Both are independent cases t A 1 2 30 12711 O B 2 D 4

1 points SCalcET8 2 6 058 Find a formula for a function that has vertical asymptotes x 6 and x 8 and horizontal asymptote y 6 f x

3 A charge particle of mass 10 gm charge 1 mili 23 coulomb is projected with velocity 30 m sec perpendicular to uniform electric field of strength 100 V m Its speed after 4 second will be 1 30 m sec 2 40 m sec 4 50 2 m sec 3 50 m sec If we have an irregularly shaned conductor as 24 10 facts and fact ci ferm 4 100 V m far ga 30 m sec fa 1 30 m sec 2 40 m sec 3 50 m sec 4 50 2 m sec afe Y SUGGE COVIC at du fam

Two objects one sliding down from rest on a smooth frictionless slope the other being thrown from the point O start their motion at the same instant Both get to the point P at the same time and at the same speed Determine the initial angle of the throw enka

Which of the following is an example of exot breed of cattle 1 Jersey 3 Frieswal 2 Sunandini 4 Karan Fries

A solid sphere of radius R is charged uniformly At 26 what distance from its surface is the electrostatic potential half of the potential at the centre 1 R 2 R2 3 R 3 4 2 R R N HT I NGANH A 3H fe for at for fagd fara fa 1 R 3 R 3 2 R2 4 2 R

If we have an irregularly shaped conductor as 24 shown and a charge is given to it choose the correct statement P afs feandurg an ander fam 1 the electric field and electric potential at P is maximum among all points of conductor 2 the electric field at P is maximum and electric potential is same at all points of conductor 3 the electric field and electric potential at P is same at all points of conductor 4 the electric field and electric potential at P is minimum among all points of conductor If an electron moves in the direction of electric 25 afe and can ia faga in ferm f 2 P 1 aga aga agafava ale fa on m ne questionpape farofa 3 aga a daga faca acest and fargen 4 aga vai agafava ale face

6 57 A body on the equator of a planet weighs half of its weight at the pole The density of matter of the planet is 3 g cm Determine the period of rotation of the planet about its axis Ans 3 16 x 104 rad s X

A current of 3 2 mA is flowing through a 37 conductor then number of free electrons moving per see is 1 2 10 9 3 2 10 8 slast Course Il 2 2 10 6 4 2 10 7 4 20 N mAuft f 3 2 dve faster you recen 1 2 10 9 3 2 10 2 2 10 4 2 10

A milliammeter with full scale deflection at 100 A has a resistance of 750 Find the resistance necessary to use the instrument as a voltmeter to read 0 50 volts a resistance of 499 25 kn is to be connected in series

The resistance of a moving coil galvanometer is 99 and the current for its full scale deflection is 100 A To con vert the galvanometer into an ammeter to read a maxi mum current of 10 mA what should be the resistance to be connected in parallel with it 10

A conducting shell S having charge Q is 18 Q surrounded by an uncharged concentric conducting spherical shell S Let the potential difference between S and S be V If shell S is now given a charge 3Q the new potential difference between the same two shell is 1 V 2 2V 3 4V 4 2V ancar v 3Q fear ang at at ayat m 1 V questionpt 2 2V 3 4V 4 2V

An object is projected from ground with speed u angle 0 with horizontal the radius of curvature its trajectory at maximum height from ground is 1 3 u sin 20 g u sin 0 2 u cos 0 2 g u sin 0

The resistance of a galvanometer is 100 and it shows full scale deflection for 1 mA current What is the resistance of the shunt to be used to convert this instrument into an ammeter to read current up to 10 A HS 05 0 001

A solid sphere is moving and it makes an elastic collision with another stationary sphere of one fourth of its own radius After collision it comes to rest The ratio of the densities of materials of second sphere and first sphere is 1 4 2 8 3 16 4 64