JEE Questions for Physics Moving Charges And Magnetism Quiz 1 - MCQExams.com

If a current is passed in a spring, it
  • gets compressed
  • get expanded
  • oscillates
  • remains unchanged
Toroid is
  • ring shaped closed solenoid
  • rectangular shaped solenoid
  • ring shaped open solenoid
  • square shaped solenoid
A straight conductor carrying current I. If the magnetic field at a distance r is 0.4 T, then magnetic field at a distance 2r will be
  • 0.4 T
  • 0.1 T
  • 0.8 T
  • 0.2 T
A current flows in a conductor from East to West. The direction of the magnetic field at a point above the conductor is
  • towards East
  • towards West
  • towards North
  • towards South
A wire oriented in the East-West direction carries a current eastward. Direction of the magnetic field at a point to the south of the wire is
  • vertically down
  • vertically up
  • North - East
  • South - East
If in a circular coil A of radius R, current i is flowing and in another coil B of radius 2R a current 2i is flowing, then the ratio of the magnetic fields, BA and BB produced by them will be
  • 1
  • 2
  • 1/2
  • 4
Magnetic field
  • can increase the speed of charge particle
  • can accelerate a charge particle
  • Both (and (are correct
  • Both (and (are incorrect
A charged particle enters in a magnetic field whose direction is parallel to velocity of the particle, then the speed of this particle
  • in straight line
  • in coiled path
  • in circular path
  • in ellipse path

Physics-Moving Charges and Magnetism-82219.png

  • Physics-Moving Charges and Magnetism-82220.png
  • 2)
    Physics-Moving Charges and Magnetism-82221.png

  • Physics-Moving Charges and Magnetism-82222.png

  • Physics-Moving Charges and Magnetism-82223.png
A solenoid has length 0.4 cm, radius 1 cm and 400 turns of wire. If a current of 5 A is passed through this solenoid, what is the magnetic field inside the solenoid?
  • 6.28 × 10-4 T
  • 6.28 × 10-3 T
  • 6.28 × 10-7 T
  • 6.28 × 10-6 T
The magnitude of the magnetic field inside a long solenoid is increased by
  • decreasing its radius
  • decreasing the current through it
  • increasing its area of cross-section
  • introducing a medium of higher permeability
  • decreasing the number of turns in it
A long solenoid with 10 turn/cm and a radius of 7.0 cm carries a current of 20.0 mA. A current of 6.0 A exists in a straight conductor located along the central axis of the solenoid. At what radial distance from the axis will the direction of the magnetic field be at 45° to the axial direction?
  • 4.8 cm
  • 8.1 cm
  • 9.9 cm
  • 10.6 cm
A direct current I flows along the length of an infinitely long straight thin walled pipe, then the magnetic field is
  • uniform throughout the pipe but not zero
  • zero only along the axis of the pipe
  • zero at any point inside the pipe
  • maximum at the centre and minimum at the edge

Physics-Moving Charges and Magnetism-82229.png
  • 5
  • 6
  • 3
  • 4
When current passed through a circular wire prepared from a long conducting wire, the magnetic field produced at its centre is B. Now a loop having two turns is prepared from the same wire and the same current is passed through it. The magnetic field at its centre will be
  • 4B
  • 2)
    Physics-Moving Charges and Magnetism-82231.png

  • Physics-Moving Charges and Magnetism-82232.png
  • 16B
A long solenoid of length L has a mean diameter D. It has n layers of winding of N turns each. If it carries a current I, the magnetic field at its centre will be
  • proportional to D
  • inversely proportional to D
  • independent of D
  • proportional to L
The magnetic field on the axis of a long solenoid having n turns per unit length and carrying a current i is
  • μ0 n i
  • μ0 n2 i
  • μ0 n i2
  • None of these
A length of wire carries a steady current. It is bent first to form a circular coil of one turn. The same length is now bent more sharply to give a double loop of smaller radius. The magnetic field at the centre caused by the same current is
  • double of its first value
  • quarter of its first value
  • four times of its first value
  • same as the first value
A steady electric current is flowing through a cylindrical conductor
  • the magnetic field in the vicinity of the conductor is zero
  • the electric field in the vicinity of the conductor is non-zero
  • the magnetic field at the axis of the conductor is zero
  • the electric field at the axis of the conductor is zero
If two parallel wires carry current in opposite directions
  • the wires attract each other
  • the wires repel each other
  • the wires experience neither attraction nor repulsion
  • the forces of attraction or repulsion do not depend on current direction
The magnetic field at the centre of a circular current carrying conductor of radius r is Bc . The magnetic field on its axis at a distance r from the centre is Ba . The value of Bc : Ba will be
  • 1 : √2
  • 1 : 2√2
  • 2√2 : 1
  • √2 : 1
A circular conductor of radius 5 cm produces a magnetic field of 7 × 10-6 T. The current flowing through the conductor is
  • 3.0 A
  • 2.25 A
  • 4.5 A
  • 0.56 A
A current of 10 A is passing through a long wire which has semicircular loop of the radius 20 cm as shown in the figure. Magnetic field produced at the centre of the loop is
Physics-Moving Charges and Magnetism-82239.png
  • 10 πμ T
  • 5 πμ T
  • 4 πμ T
  • 2 πμ T

Physics-Moving Charges and Magnetism-82241.png

  • Physics-Moving Charges and Magnetism-82242.png
  • 4
  • 1

  • Physics-Moving Charges and Magnetism-82243.png
A current I flows along the length of an infinitely long, straight, thin walled pipe. Then
  • the magnetic field is zero only on the axis of the pipe
  • the magnetic field is different at different points inside the pipe
  • the magnetic field at any point inside the pipe is zero
  • the magnetic field at all points inside the pipe is the same, but not zero
A circular coil carrying a certain current produces a magnetic field B0 at its centre. The coil is now rewound so as to have 3 turns and the same current is passed through it. The new magnetic field at the centre is

  • Physics-Moving Charges and Magnetism-82245.png
  • 9B0

  • Physics-Moving Charges and Magnetism-82246.png
  • 3B0
An electric current is passed through a circuit containing two wires of the same material, connected in parallel. If the lengths and radii of the wires are in the ratio of 4/3 and 2/3, then the ratio of the currents passing through the wire will be
  • 3
  • 1/3
  • 8/9
  • 2
The magnetic field at the centre of a current carrying circular loop is B. If the radius of the loop is doubled, keeping the current same, the magnetic field at the centre of the loop would be

  • Physics-Moving Charges and Magnetism-82249.png
  • 2)
    Physics-Moving Charges and Magnetism-82250.png
  • 2B
  • 4B
Two long parallel conductors carry currents in opposite directions as shown. One conductor carries a current of 10 A and the distance between the wires is d =10 cm. Current I is adjusted, so that the magnetic field at P is zero. P is at a distance of 5 cm to the right of the 10 A current. Value of I is
Physics-Moving Charges and Magnetism-82252.png
  • 40 A
  • 30 A
  • 20 A
  • 10 A
A wire in the form of a circular loop of one turn carrying a current produces a magnetic field B at the centre. If the same wire is looped into a coil of two turns and carries the same current, the new value of magnetic induction at the centre is
  • 3B
  • 5B
  • 4B
  • 2B
For the magnetic field to be maximum due to a small element of current carrying conductor at a point, the angle between the element and the line joining the element to the given point must be
  • 0°
  • 90°
  • 180°
  • 45°
A narrow beam of protons and deuterons, each having the same momentum, enters a region of uniform magnetic field directed perpendicular to their direction of momentum. The ratio of the radii of the circular paths described by them is
  • 1 : 2
  • 1 : 1
  • 2 : 1
  • 1 : 3
A proton and an a-particle, accelerated through the same potential difference, enter a region of uniform magnetic field normally. If the radius of the proton orbit is 10 cm, then radius of a-particle is
  • 10 cm
  • 10√2 cm
  • 20 cm
  • 5√2 cm
An electron moves at right angle to a magnetic field of 5 × 10-2 T with a speed of 6 × 107 m/s. If the specific charge of the electron is 1.7 × 1011 C/kg. The radius of the circular path will be
  • 2.9 cm
  • 3.9 cm
  • 2.35 cm
  • 2 cm
A charged particle experiences magnetic force in the presence of magnetic field. Which of the following statements is correct?
  • The particle is moving and magnetic field is perpendicular to the velocity
  • The particle is moving and magnetic field is parallel to the velocity
  • The particle is stationary and magnetic field is perpendicular
  • The particle is stationary and magnetic field is parallel
If a velocity has both perpendicular and parallel components while moving through a magnetic field, what is the path followed by a charged particle?
  • Circular
  • Elliptical
  • Linear
  • Helical
A cyclotron is operated at an oscillator frequency of 24 MHz and has a dee radius of 60 cm. Find the magnitude of the magnetic field needed for deuterons to be accelerated in the cyclotron
  • 6.4 T
  • 3.2 T
  • 1.6 T
  • 0.9 T
An electrically charged particle enters into a uniform magnetic induction field in a direction perpendicular to the field with a velocity v. Then, it travels
  • in a straight line without acceleration
  • with force in the direction of the field
  • in a circular path with a radius directly proportional to v2
  • in a circular path with a radius directly proportional to its velocity
A beam of protons is moving horizontally towards you. As it approaches you, it passes through a magnetic field which is directed upwards. As you see it, the magnetic field will deflect the beam to the
  • right
  • left
  • top
  • bottom
An α-particle and a proton moving with the same kinetic energy enter a region of uniform magnetic field at right angles to the field. The ratio of the radii of the paths of a-particle to that of the proton is
  • 1 : 8
  • 2 : 1
  • 1 : 2
  • 1 : 4
An electron and a proton are moving on straight parallel paths with same velocity. They enter a semi-infinite region of uniform magnetic field perpendicular to the velocity. Which of the following statement(s) is/are true?
  • They will never come out of the magnetic field region.
  • They will come out travelling along paths.
  • They will come out at the same time.
  • They will come out at different times.
A particle of charge e and mass m moves with a velocity v in a magnetic field B applied perpendicular to the motion of the particle. The radius r of its path in the field is

  • Physics-Moving Charges and Magnetism-82264.png
  • 2)
    Physics-Moving Charges and Magnetism-82265.png

  • Physics-Moving Charges and Magnetism-82266.png

  • Physics-Moving Charges and Magnetism-82267.png
A neutron, a proton, an electron and an α - particle enter a region of uniform magnetic field with the same velocities. The magnetic field is perpendicular and directed into the plane of the paper. The tracks of the particles are labelled in the figure. The electron follows the track
Physics-Moving Charges and Magnetism-82269.png
  • D
  • C
  • B
  • A
A charge + Q is moving upwards vertically. It enters a magnetic field directed to North. The force on the charge will be towards
  • North
  • South
  • East
  • West
An electron moves in a circular orbit with a uniform speed v. It produces a magnetic field B at the centre of the circle. The radius of the circle is proportional to

  • Physics-Moving Charges and Magnetism-82271.png
  • 2)
    Physics-Moving Charges and Magnetism-82272.png

  • Physics-Moving Charges and Magnetism-82273.png

  • Physics-Moving Charges and Magnetism-82274.png
Two charged particles are projected into a region in which a magnetic field is perpendicular to their velocities. After they enter the magnetic field, you can conclude that
  • the charges are deflected in opposite directions
  • the charges continue to move in a straight line
  • the charges move in circular paths
  • the charges move in circular paths but in opposite directions
Which of the following particles will describe the smallest circle when projected with the same velocity perpendicular to the magnetic field?
  • Electron
  • Proton
  • α - particle
  • Deuteron
Four charged particles are projected perpendicularly into the magnetic field with equal. Which will have minimum frequency?
  • Proton
  • Electron
  • Li+
  • He+
Proton and α-particle projected perpendicularly in a magnetic field, if both move in a circular path with same speed. Then ratio of their radii is
  • 1 : 2
  • 2 : 1
  • 1 : 4
  • 1 : 1
Under the influence of a uniform magnetic field a charged particle is moving in a circle of radius R with constant speed v. The time period of the motion
  • depends on v and not on R
  • depends on both R and v
  • is independent of both R and v
  • depends on R and not on v
0:0:1


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