# Magnetic Field Questions and Answers

Physics

Magnetic Fieldand the charged particle is moving along the positive x axis Fig 4 4 the magnetic field is parallel to the positive y axis which way would the Lorentz force be for a an electron negative charge b a proton positive charge Z XX xxxx xxx xx x y xxxxx XX XX xx xXxxxx xxxxxxxxx FIGURE 4 4 Xxxxxxxxxxxx xxxxxxxxxxx xxxxxxxxx xxxxxxxx XX x Solution The velocity v of particle is along the x axis while B the magnetic field is along the y axis so v x B is along the z axis screw rule or right hand thumb rule So a for electron it will be along axis b for a positive charge proton the force is along z axis

Physics

Magnetic FieldA cyclotron accelerates deutrons The radius of the dee is 0 8 m and the frequency of the cyclotron s oscillator s IMHZ a Find the number of times a deutron enters into the gap between the dees in one second

Physics

Magnetic FieldConsider the wire which is in a region of uniform magnetic field of magnitude B 2 3T carries a current of I 18A as shown in the figure below If 47cm a 45 and is making an angle of 0 22 degress determine the net force acting on the wire Express your answer in units of N using one decimal places y x 18 X l X X 0 X X X X X

Physics

Magnetic FieldA conducting ring of radius L 2m is placed on X Y plane having its centre at the origin as shown in the figure A uniform magnetic field 5T k exists in the space A conducting rod PQ of mass M and length 2L is placed along the diameter of the rail as shown Rod is free to rotate about z axis on the smothering A resistance R is connected to the centre O and periphery of the ring At t 0 the rod PQ is given an angular velocity 1 k rad sec Find the ratio of the numerical values of the charge flown through the resistor to the heat generated through the resistor during the time interval the rod keeps on rotating P R www Z O

Physics

Magnetic FieldThe plane of the circular current carrying loop having radius 1 52 cm and mass 2 5 g is making an angle of 25 with the uniform magnetic field having a magnitude of 4 6 10 T The current passing through the loop is 3 4 A Calculate the magnitude of the angular acceleration of the circular loop nswer a 71 rad s b 18 rad s2 c 24 rad s d 18 rad s A

Physics

Magnetic FieldA long straight wire carries current I There is quarter ring of radius 3a present near it as shown Find force on the quarter ring Quarter ring is in the plane of paper and long wire is perpendicular to the plane of paper A H 11 112 TO B H 2 In 5 2 a C 3a H II In 2 5 3 D Holz I 2 In 2

Physics

Magnetic FieldA region of space has a uniform magnetic field Bk A particle having mass m and charge q enters into the region at the origin with a velocity vi vk a Write the velocity of the particle at time after it enters the field b Write the co ordinates of the particle as a function of time

Physics

Magnetic FieldWhen the pressure on a given mass of liquid is increased from 3 MPa to 3 5 MPa the density of the liquid increases from 500 kg m to 501 kg m the average value of bulk modulus of liquid over the given pressure range will be MPa

Physics

Magnetic FieldA conducting rod of mass m 0 3 kg and length 4m can slide without friction on two parallel conducting rails The conducting rails are connected via an inductance L 3mH This system is placed in a region containing uniform magnetic field B 1T pointing into the plane If the rod is given an initial velocity vo 2 m s it oscillates with an amplitude A cm Find the value of 2A lellele Vo O B

Physics

Magnetic FieldA dielectric slab of thickness d is inserted in a parallel plate capacitor whose negative plate is at x 0 and positive plate is at x 3d The slab is equidistant from the plates The capacitor is given some charge As one goes from 0 to 3d 1 The magnitude of the electric field remains the same 2 The electric potential decreases continuously 3 The electric potential increases continuously 4 The electric potential increases at first then decreases and again increases

Physics

Magnetic Field3 A line charge of linear density is paste on the rim of a wheel of mass M and radius R The wheel has light non conducting spokes and is free to rotate about a vertical axis A uniform magnetic field extends over a circular region centered at the centre of wheel given by B Bok for r a and B for r a 1 B MR Z What is angular velocity acquired by the wheel as the field is suddenly switched off A a B 2 MR 22 m p

Physics

Magnetic FieldA field of strength 5x10 ampere turns meter acts at right angles to the coil of 50 turns of area 102 m The coil is removed from the field in 0 1 second then the induced e m f in the coil 1 0 1 V 3 1 96V 2 0 2V

Physics

Magnetic FieldA straight 10 cm wire bent at its midpoint so as to form an angle of 90 carries a current of 15 A It lies in the xy plane in a region where the magnetic field is in the positive z direction and has a constant magnitude of 3 0 mT What is the magnitude of the magnetic force on this wire Select one Oa 6 4 mN Ob 3 2 mN O c 4 2 mN d 2 1 mN O

Physics

Magnetic Fieldproton travels with a speed of 4 95 x 106 m s at an angle of 58 with the direction of a magnetic field of magnitude 0 170 T in the positive x directi a What is the magnitude of the magnetic force on the proton N b What is the proton s acceleration Give the magnitude m s

Physics

Magnetic FieldA straight wire carrying current i is turned into a circular loop If the magnitude of magnetic moment associated with it in M K S unit is M the length of wire will be 1 4 iM 2 3 4M 4 i VM

Physics

Magnetic Field4 Spe The time period of a charge particle which is projected in a magnetic field B with velocity at an angle 0 with the direction of magnetic field is NCERT Pg 138 2 m 1 qB 2 m cose 24 2 m qB sine 2 m 4 qB tan0