Physics Questions

spiral paths when encountering the magnetic field of astrophysical objects or planets one example being Earth s magnetic field The curved paths of charged particles in magnetic fields are the basis of a number of phenomena and can even be used analytically such as in a mass spectrometer Q 3 An a particle and proton having same momentum enter into a region of uniform magnetic field and move in a circular path The ratio of the radii of curvature of their paths 1 Point 0000 1 1 4 1 2 4

A bulb and an inductor are connected in series to an ac source through a switch The bulb glows with certain brightness when the switch is closed If a soft ferromagnetic material with large permeability is introduced into the inductor coil the brightness of the bulb will A decrease B increase C remain the same bogomor

33 A charge q is fixed near by two point charges Q each as shown The net force experienced by the charge is equal to 0 1 01 1 2Qq 2 4 EO 1 3Q Q 0 90 9 2 1 3Qq 4 EO 2 1 1 Zem

One plate of a capacitor is connected to a spring as shown in figure Area of both the plates is A In steady state separation between the plates is 0 8d spring was unstretched and the distance between the plates was d when the capacitor was uncharged The force constant of the spring is approximately E 000000

16 A uniform electric field of strength 60 V m exists in X Y plane making an angle 120 with positive x axis The potential difference between points P 2 3 anc Q 4 1 is given by 1 60 3 3 V 3 30 3 3 V 2 60 3 3 V 4 30 3 3 V

Assertion A If an electron and proton enter a magnetic field with equal momentum then the paths of both of them will be equally curved Reason R The magnitude of charge on an electron is same as that on a proton 1 Point 000 Both A and R are true and R is the correct explanation of A Both A and R are true but R is not the correct explanation of A A is true but R is false Ise and R is also false

strikes the ground What is the distance travelled by the ball in the last 3s g 9 8 m s 58 8 m s 132 3 m A body is dropped from a height of 176 4 m Find the distance covered by it in the last second of its motion With what velocity will the body strike the ground g 9 8 m s 53 9 m 58 8 m s lost second of its motion Find

14 Two metallic cylinder made of same material and radii r and 2r are joined as shown in figure If top end is fixed and lower end of cylinder B is twisted by angle 8 then angle of twist for cylinder A is both cylinder have same length 1 2 3 4 15 16 0 16 15 17 0 0 160 17

A 3 kg mass is moving in a plane with its x and y coordinates given by x 5t 1 and y 3t 2 Then at t 2 seconds A The net acceleration is 10 26m s B The net acceleration is 37 36m s C The net force acting on 3 kg mass is 112 08 N D The net force acting on 3 kg mass is 146 N

Calculate the minimum velocity which should be provided at lowermost point w r t cabin so that particle can just complete the circle 1 zgl 2 Cabin moving upward with acceleration g 2 A g D New Lig

Two blocks of masses m and 2m are placed in contact on a smooth horizontal surface as shown Two forces of magnitudes 10 N and 16 N respectively are applied on system as shown in figure Normal contact force between the blocks is 10 N 16 N 16 N O 14 N O 12 N m 2m

me equipotential surfaces are shown in the region The electric field intensity in the region is given by 20 V 40 V 60 V 80 V Ja fa fa fe 60 60 60 60 30 cm 60 cm 90 cm 200 3 3 200 V m 1 V m 400 3 3 4 100 V m 2 V m

35 If a metallic sphere gets cooled from 62 C to 50 C in 10 minutes and in the next 10 minutes gets com 42 C then the temperature of the surroundings is 1 30 C 3 26 C 2 4 36 C 20 C

3 A Gravitational potential is constant everywhere inside a spherical shell R Gravitational field inside a spherical shell is zero everywhere

The figure shows the P V plot of an ideal gas taken through a cycle DCBAD then 6Po P 5Po 4Po O O O O L 1 A I I C Vo 2V 3Vo B All of the above I 1 1 maximum temperature will occur during the process C B A negative work is done by the gas in the cycle DCBAD heat flows out of the gas during C B A

Three blocks of masses m m and m are connected by a massless string as shown The are pulling with a force F 40 N If m 10kg m 6kg and m 4kg then tension 7 and 7 will be A 10 N m B 20 N 10 12203 C 32 N D 40 N

A man standing at the top of a building throws a ball vertically upwards with a velocity of 14 m s The ball reaches the ground 4 6s later What is the maximum height reached by the ball How high is the building With what velocity will the ball strike the ground g 9 8 m s 49 2 m above ground 39 2 m 31 05 m s

Two masses M m and Mm are attached to the ends of a light inextensible str and the string is made to pass over the surface of a smooth fixed pulley When the masses are released from rest Then acceleration and tension in the string A gm M B 2gm M C 2 M m g 2M Mg 2m

can even be used analytically such as in a mass spectrometer Q 4 A neutron a proton an electron and an a particle enter in a region of uniform magnetic field with equal velocities The magnetic field is perpendicular and directed into the paper The tracks of the particles are shown in figure The electron will follow the track 1 Point A B U D 5

A mass of 4 kg lies on a plane making an angle 30 to the horizontal Resolve its weight along and perpendicular to the plane Assume g 10 m s 1 In figure the component of weight along the plane mg sin 30 4 10x 20N The component of weight perpendicular to plane mg cos30 2x10x 3 2 mg sin30 30 Ymg mgcos30

A rocket of initial mass 6000 kg ejects gases at rate of 16 kg sec with constant relative speed of 11 km sec What is the acceleration of rocket 1 minute after the blast 1 25 m s 2 50 m s 3 10 m s 4 35 m s New Lig

Q A particle moving with velocity is acted by three forces shown by the vector triangle PQR The velocity of particle will NEET 2019 a Remain constant b Change according to the smallest force QR c Increase d decrease P R

A body is thrown vertically upwards a velocity the instants when it goes past a point 100 m from the ground in its upward and downward journey g 9 8 m s 4 28 s A stone is thrown vertically upwards with a velocity of 20 m s When will its speed be 6 m s and at what altitude 1 43 s 2 65 s 18 6 m

Example 12 A wire of length I and cross sectional area A is suspended at one of its ends from a ceiling What will be its strain energy due to its own weight if the density and Young s modulus of the material of the wire be d and Y Solution Consider an elemental length of the wire of length dx at a distance x from the lower end This length is acted upon by the external force equal to the weight of the portion of wire below foron E in x Ada la Cilibriu

2 Points 10 3 N 2 5 x 10 3 N 0 Three long straight parallel wires carrying current are arranged as shown in the figure The force experienced by a 25 cm length of wire C is 1 5 x 10 3 N 30 A 3 cm 2 cm 10 A 20 A

A Field created by the point mass in its surroundings is a non uniform gravitational field and it is dependent R Since the field is E GM r on r hence Non uniform

Consider the infinite Atwood s machine shown below A string passes over each pulley with one end attached to a mass and the other end attached to another pulley All the masses are equal to m and all the pulleys and strings are massless The masses are held fixed and then simultaneously released What is the acceleration of the top mass m m

A 4 the horizontal After 2 s the ball is moving at an angle of 30 with the horizontal The speed of projection of the projectile may be equal to 1 66 9 m s 2 17 9 m s 3 28 m s 4 Both 1 and 2

meet After 4 s 78 4 m from top From a height of 98 m a body is dropped to fall freely and at the same instant a body is projected vertically upwards from the ground with a velocity of 49 m s along the same path Find when and where the two bodies meet After 2 s height of 76 4 m

41 A charge q is kept midway between two charges C each on the line joining two charges The system of charges are in equilibrium if q is 1 q 3 9 Q 4 Q 2 52 2 9 4 9 1 2 4 5

From the top of a tower 100 m high a ball is dropped At the same time another ball is projected vertically upwards from the ground with a velocity of 25 m s Find when and where the two will After 4 s 78 4 m from top meet

charge of magnitude Q but positive and negative altemately as shown Then the electric field at centre of ring will be A kw B B R where 2k 3k Y D None of these where 1 3Q TR where 1848 TR

13 The value of coefficient of volume expansion of glycerin is 5 x 10 4K 1 The fractional change in the density of glycerin for a rise of 40 C in its is Re AIPMT 2015 temperature 1 0 010 3 0 020 2 0 015 4 0 025 ET AIIMS

A projectile is projected at an a with the horizontal and with a speed of u The angle made by velocity vector with horizontal as a function of time is best related as 1 tan 3 tan usina gt u cos a gt usina gt 2 tan 4 tan usina u cos a gt usina

1 A 3 C 4 D Breaking stress for a material is 2 x 10 N m What maximum length of the wire of this material can so that the wire does not break by own weight Density of material 5 x 10 kg m 1 1 km 2 2 km 3 3 km 4 4 km

14 An electron is projected with uniform velocity along the axis of a current carrying long solenoid Which of the following is true 1 Point The electron will be accelerated along the axis The electron path will be circular about the axis The electron will experience a force at 45 to the axis and hence execute a helical path The electron will continue to move with uniform velocity along the axis of the solenoid

42 Two identical charged pendulums are inclined at angle 30 and 60 from infinite sheet of charge of surface charge densities o and o respectively as shown The ratio of o and o is CT 30 60

In a moving coil galvanometer the deflection on the scale by a pointer attached to the spring is 1 Point NA KB I NAB K I N KBA I KB NA I 13

method IST India Standard Time is linked to a set of atomic clocks the no of clocks are 1 One 3 Three 2 Two 4 Four

12 x m 24 6 8 10 12 14 16 18 20 22 t sec What is nature of acceleration between t 18 s and t 20 s is above diagram 1 Positive 2 Negative 3 Zero 4 None of these ph which of following physica

A convex mirror and a concave mirror of radius 10 cm each are placed 15 cm apar facing each other An object is placed midway between them If the reflection first takes place in the concave mirror and then in convex mirror the distance of the final image from the pole of the convex mirror in cm is

A simple pendulum when reaches its maximum angular displacement of 60 from the vertical is hit by a bullet moving horizontally with velocity 200 m s The bullet comes out of the bob horizontally with velocity 100 m s Find velocity of the bob immediately after the bullet comes out Neglect loss of mass of the bob due to piercing by the bullet Mass of the bob is 10 times of that of the bullet bullet bob

No 17 The magnetic field in a region is given by B Bo the loop is 2 B v d 2a B v d 2a B v d a B v d 2a View In English k A square loop of side d is placed with its edges along the x and y axes The loop is moved with a constant velocity V voi The emf induce y 6 d d

4 s 2 s 29 4 m s Find the velocity at which a rifle bullet must be fired vertically so as to reach a height of 1 km What time will elapse before the bullet passes through the firing point on its return journey 08m 140 m s 200 7 s

A galvanometer of resistance 3092 is connected to a battery of emf 2V with 1970 resistance in series A full scale deflection of 20 divisions is obtained in the galvanometer To reduce the deflection to 10 divisions the resistance in series required is 2 Points 3970 ohms 2000 ohms 4000 ohms 4030 ohms

In the following circuit the difference between the readings of ammeters A and A In amp 9p found out to be Find the value of p Assume the resistances of ammeters negligible 70 200V 100V 10002 ww A 10002 150V 90V www 10002 2000

35 A straight thin conductor is bent as shown It carriers a current of i ampere The radius of curvature of the circular arc is r meter The magnetic induction at the centre of semicircular arc Ho 4 r KING CH 0 2 infinity Hoi 4 4 T

3 In the given graph which of following physica quantities changes their sign Velocity 2V Vo 0 1 Displacement 3 Both 1 and 2 t tim 2 Velocity 4 Acceleration cortically through the

A stone attached to a rope of length 1 80 cm is rotated in vertical plane with a frequency n 240 r p m At the moment when the velocity of the stone is directed vertically upwards the rope ruptures To what further height does the stone rise The air resistance should be neglected a 10 3 m b 41 2 m V YW V 80 y 9 56 20 20 6 m v 3 2gh d 24 9 m Wz

Arrange the following in ascending order of their resistances a Ammeter of range 10 A b Ideal voltmeter c voltmeter of range 100 V d Ammeter of range 1 mA 1 a b c d 3 a d c b 2 a d b c 4 b c a d