Magnetism and Matter Questions and Answers

Second power of distance The force between two short magnets along their line joining parallel to the axis will be inversely proportional to Third power of distance Fourth power of distance Zero power of distance questions Each question has 4 choices 1 2 3 and 4 out of which only one is correct Solution Answer 3 Read More

AOB is a right angled isosceles triangle with sides OA OB 2 a in xy plane It is carrying current as shown The magnetic induction at the point 0 0 a B due to current in AOB is B B due to current in BA is B C due to current in AOB is B D due to current in BA is B Hoi Hoi 4 6 a Hoi i j 3k Hol 2 3 a i j 2k

19 A particle having charge 100 times that of an electron is revolving in a circular path by radius 0 8 m with one rotation per second The magnetic field produced at the center is D O a 10 16 0 b 10 17 po Oc 10 15 po O d 10 17 po 4

e 25 Current is flowing in a wire frame kept as shown in the figure where EDCF is in y z plane and A is in x z plane Current in the wire frame is i and length of each side is a Find the magnetic mor E F AY A C B

A rod length 1 m is kept inclined at an angle of 60 with the uniform magnetic field of strength 0 5 tesla If the rod is moved with a velocity 10 m s perpendicular to the field then the induced e m f is A 2 5 volt B 4 3 volt C 7 5 volt D 10 volt 60 60 B

The equation for an instantaneous t current in a material is given by i 5e A Calculate the amount of total charge flown through the material during the time interval t 0s to t S A 2Cb B 5Cb

A disc of uniform surface charge density is rotating about an axis passing through its centre and perpendicular to its plane with const angular velocity w The ratio of its magnetic moment and its angular momentum is found to q nm Find the value of n where q total charge on the disc m mass of disc

17 A current carrying square loop of side a is place in a uniform magnetic field B in x y plane a shown in the figure The loop carries a current c 2A in clockwise sense The torque acting a the loop is all quantities are in Sl units 1 Ba i j 2 1 P B 2 Ba i j 4 28 2 1

9 A long straight wire of radius a carries a steady current I The current is uniformly distributed across its cross section the ratio of the magnetic field at and a 2 2a is a 4 b 4 c 1 d 1 2

3 Needles N N and N3 are made of ferromagnetic a paramagnetic and a diamagnetic substance respectively A magnet when brought close to them will a attract all three of them b attract N and N strongly but repel 3 c attract N strongly N weakly and repel N3 weakly d attract N strongly but repel N and N3 weakly

2 The magnetic moment of a bar magnet of length 10cm and cross sectional area 4 sq cm is 2 A sq m The magnetization of bar magnet in SI system of unit is O 80000 O 500000 O 800000 O 50000

19 A specimen of iron of permeability 8 x 10 3 weber A m is placed in a magnetic field of strength 160 A m Magnetic induction in this iron is 1 0 8 Wb m 3 1 28 Wb m 2 5 x 105 Wb m 4 20 103 Wb m

11 The core of a toroid having 3000 turns has inner and outer radii of 16 cm and 17 cm respectively The magnetic field in the core for a current of 0 07 A is 2 5 T What is relative permeability of the core

done in rotating the coil through 90 It is suspended freely in uniform magnetic field 0 2 T A bar magnet of magnetic dipole moment 10 Am is in stable equilibrium If it is rotated through 30 find its potential energy in new position Given B 0 2 TJ

Blocks B and C of mass 2m and 3m respectively are connected by a spring of force constant k block A of mass mis released with zero speed from height H above block B which is at equilibrium The collision of A and B is completely inelastic What is the minimum mg value of H in m so that block C is just able to lift off ground during subsequent motion Given 10cm k 772 2m B 3m A k C

A uniform electric field and a uniform magnetic field are acting along the same direction in a certain region If an electron is projected in the region such that its velocity is pointed along the direction of fields then the electron 2011 will turn towards right of direction of motion speed will decrease speed will increase I G C 1 C

Our earth behaves as it has a powerful magnet within it The value of magnetic field on the surface of earth is a few tenth of gauss 1G 104 T There are three elements of Earth s magnetism Geographical North Magnetic BI North 34 Magnetic meredian i Angle of declination ii Angle of dip iii Horizontal component of Earth s magnetic field In the magnetic meridian of a certain place the horizontal component of Earth s magnetic field is 0 6 G and the dip angle is 53 The value of net magnetic field at this place is 1 0 8 G 2 0 6 G 3 1 0 G 4 2 0 G

plane electromagnetic wave travels in free space along the x direction The electric field component of the wave at a particular point of space and time is E 6 Vm long y direction Its corresponding magnetic field component B would be O 2x 10 8 T along z direction O 6 x 108T along x direction O6x 108 T along z direction O 2x 108 Talong direction

A capacitance balance is shown in the figure The balance has a block pulley system attached on one side and a capacitor that has a variable gap width on the other side Assume upper plate of the capacitor has negligible mass When the separation between the plate is 1 meter the attractive force between the plates 5 balances the pulley block system Then find value of Vin 20 volts EMF of battery Take area of the plate m 360 10kg 4m 40 3 kg 5kg 4m

A short bar magnet experiences a torque of magnitude 0 50 Nm where it placed in a uniform magnetic field of 0 25 T at angle of 30 with the direction of field The magnetic moment of the magnet is 2 Am 3 Am 4 Am

A copper rod of mass m slides under gravity on two smooth parallel rails distance apart and set an angle to the horizontal 0 At the bottom the rails are joined by a resistance R in figure There is a uniform magnetic field B perpendicular to the plane of the rails The terminal velocity of rod is

Magnetic susceptibility of paramagnetic substance is in order of 10 5 105 103 hr min O 10

Sir pls explain the 2nd and 4th options Which of the following is correct 1 The magnetic field lines need not be perpendicular to the surface from which they originate 8 2 3 Complete magnetic shielding is not possible Curie point is the critical temperature below which a substance behaves as super conductor 4 A bar magnet s dipole moment can be always determined in the presence of an external field kod by 2589921 aslid Standard VII Stream ICE I Jul 29 2021 at s

Orientation of two identical small bar magnet of magnetic moment M is as shown in figure The magnitude of magnetic field at the point O which lies on equatorial line of one magnet and axial line of another magnet is r size of magnet NCERT Pg 177 1 Nr S MOM 4 r 5M O SAN 2 3 M 4 r r3 MOM

An electron is moving in an orbit of radius R with frequency f The magnetic moment produced is given by O f R O2nf R

Conductor of length has shape of a semi cylinder of radius R I Cross section of the conductor is shown in the figure Thickness of the conductor is t R and conductivity of its material varies with angle 0 according to the law o o cose where is a constant If a battery of emf is connected across its end faces across the semi circular cross sections the magnetic induction at the mid point O of the axis of the semi cylinder is c d e R 1 da ARTE HART Het 81 R Cose B HooEt 41 E C HooEt 2 0 Et D

A proton is thrown in an uniform magnetic field B at an angle of 90 with the direction of field Then path of particle will be O Parabolic O Spiral O Circle O Linear

D A biconvex lens with focal length f in air and refractive index of 1 5 is floating on the surface of a deep pond of water refractive index 1 33 If an object is placed at a height of 2f vertically above the lens then the distance between the lens and the image is A f B 2f C less than 2f D greater than 2 f

A conducting disc of conductivity o has radius a and thickness 8 A unifom magnetic field B applied in a direction perpendicular to the plane of the disc If the magnetic field changes wit time at the rate of dB dt then the power dissipated in the disc due to the induced current A C noo dB dt 8 oo dB dt B D oo dB 12 dt o dB 6 dt

A dip circle is placed in magnetic meridian then the magnetic needle will align 1 Horizontally 2 2 Vertically 3 In the direction of earth s magnetic field A dip circle is placed perpendicular to the magnetic meridian then the magnetic needle will align 4 Perpendicular to earth s magnetic field

Shown below is the picture of a solenoid Direction of current is shown Can you tell which side of this solenoid acts as a North pole A Left side B Right side C Insufficient information Q2 OPTIONS Left electric currenc Right

82 A uniform conducting wire of length 18a and resistance R is wound up as current carrying coil in the shape of a regular hexagon of sides a If the coil is connected to a voltage source Vo then the magnetic moment of coil is V a 6 3 a A m R 9 3 Va 2 R 1065 c d 7 3 V a Am A m 2 R 11 3 Va Am 2 R a a a 60 a d 999 9 88 Two moving coil particular R 10 92 N 30 R 14 Q2 N 42 The spring consta What is the ratio sensitivity of M tom a 1 4 1 c 2 8 2 89 The value of curren is a galvanometer w

The magnitude of the magnetic dipole moment associated with a square shaped loop carrying a steady current 0 5 A is 1 0 Am If this loop is changed to a circular shape with the same current 0 5 A passing through it then find the magnetic dipole moment

Mark out the incorrect options 1 Diamagnetism exhibits in all materials 2 Magnetic suscptability m of super conductor is 1 3 Minimum potential energy of magnetic moment is zero 4 Magnetic field and magnetic moment are axial vector for current camning coil 14 1 ff 1 2 aftremert a great f x 3 gratis ya qan feat vi i 4 urant use for iz firm a quita

A metal rod of mass 10 gm and length 25 cm is suspended on two springs in a vertical plane as shown in figure The springs are extended by 4cm When a 20 ampere current passes through the rod it rises by 1 cm Determine the magnetic field in milli Tesla assuming acceleration due to gravity to be 10 m s 000000 X X k T X T

A cyclotron is operating with a flux density of 3 Wb m2 The ion which enters the field is a proton having mass 1 67 x 10 27 kg If the maximum radius of the orbit of the particle is 0 5m find the maximum velocity of the proton I 1 43 m s 1 43 km s 1 43 cm s 1 43 108 m s

A vibration mangetometer placed in magnetic meridian has a small bar magnet The magnet executes oscillations with a time period of 2 sec in earth s horizontal magnetic field of 24 microtesla When a horizontal field of 18 microtesla is produced opposite to the earth s field by placing a current carrying wire the new time period of manget will be Question Type Single Correct Type 1 2 4S 1S 25

eld given tron has eacting Field B each of is the oth of e the on in 4 45 A thin 50 0cm long metal bar with mass 750g rests on but is not attached to two metallic supports in a 0 450T magnetic field as shown in figure 4 262 A battery and a resistance R 25 092 in series are connected to the supports BO R ww iB 4T 4 48 initiall 0 8357 of the is par Figure 4 262 a What is the largest voltage the battery can have without breaking the circuit at the supports Ans b The battery voltage has this maximum value calculated Decreasing the resistance to 2 092 find the initial acceleration of the bar Ans a 817 5V b 112 8m s 49 of is is 2 pla trap

28 A U tube of uniform square cross sectional side a and length of base L has a mercury in it Current I is passed between lower side of base to upper side of base of U tube A magnetic field B is applied across horizontal section perpendicular to the plane of U tube The difference in mercury levels is Given p density of mercury a L 3 BI 2BI B 2 pga pga A C BI pga D 4B1 pga

A small particle is given an initial velocity vo 10 m s along the tangent to the brim of a fixed smooth hemisphere bowl of radius ro 15 2 m as shown in the figure The particle slides on the inner surface and reaches point B a vertical distance h 15 m below A and a distance r from the vertical centerline where its velocity v makes an angle with the horizontal tangent to the bowl through B If 0 15 K Find the value of K take g 10 m s vertical centre line

5 3 is placed at rest horizontally A smooth disc of mass M and radius on a smooth horizontal surface A massless pin is fixed at point P at a distance L 2 from centre O of the disc as shown in the figure Now a thin uniform rod of mass M and length L is placed horizontally on the surface of the disc parallel to the line OP such that its mid point and centre O of the disc just coincide as shown in figure Now rod has given angular velocity o 24 rad sec in counter clockwise direction as shown As a result the end of the rod strikes the pin P and sticks to it rigidly Calculate the angular velocity of disc just after collision T Fir JETE

3 If an electron of charge e is moving along X direction and magnetic field is along Z direction then the magnetic force acting on the electron will be along a X axis b X axis c Y axis d Y axis

Phy Section A This section contains 35 SINGLE CORRECT T questions Each question has 4 choices 1 Read More e magnetic lines of force inside a bar magnet From South pole to North pole From North pole to South pole Intersecting each other

A magnet is being brought near a circular coil of radius 10 cm having 10 turns and of resistance 100 along its axis Due to this if the magnetic flux density linked with the coil ncreases from 0 1 Wb m 2 to 0 5 Wb m 2 in 1 s find 10 ut the current induced in the coil 125 6 mA

The current in a primary coil increases by 20 A in 0 1 s If the average emf induced in the secondary coil be 100 V determine the mutual inductance between the coils and the change in magnetic flux in the secondary coil 0 5 H 10 Wb

The distance between the extremities of the two wings of an aeroplane is 30 m It is flying horizontally with a velocity of 1080km h The vertical component of earth s magnetic field in that region is 4 5 10 5 T Find the emf induced across the extremities of the two wings 10 4051

A thin lens produces a sharp image of an object on the wall The distance between the object and the wall is 9 times the distance of the wall from the nearest focal point The object magnification is A B 1 NIN wit D 12 13 C 1 210

9 A vertical circular coil of radius 5 cm carrying a current of 0 5 A is placed perpendicular to the magnetic meridian If the earth s magnetic field is 0 36 gauss what is the work done in rotating the coil through 60 Ans 70 68 n

The property possessed by only ferromagnetic substance is de ce great and a stat OPTIONS MARK FOR REVIEW CLEAR SELECTION A afer OB Hysteresis OC Susceptibility great wala Permeability greathta

If0 and 0 be the apparent angles of dip observe two vertical planes at right angles to each other the true angle of dip 0 is given by a tan 0 tan 0 tan 0 b cot 0 cot 0 cot 0 c tan 0 tan 0 tan 0 d cpt 0 cot 0 cot 0