JEE Questions for Physics Moving Charges And Magnetism Quiz 13 - MCQExams.com

The magnetic induction at a point P which is at a distance 4 cm from a long current carrying wire is 10–8 tesla. The field of induction at a distance 12 cm from the same current would be
  • 3.33 × 10–9 tesla
  • 1.11 × 10–9 tesla
  • 3 × 10–3 tesla
  • 9 × 10–2 tesla
A wire of length l is bent into a circular loop of radius R and carries a current I. The magnetic field at the centre of the loop is B. The same wire is now bent into a double loop of equal radii. If both loops carry the same current I and it is in the same direction, the magnetic field at the centre of the double loop will be
  • Zero
  • 2B
  • 4B
  • 8B
Two concentric circular coils of ten turns each are situated in the same plane. Their radii are 20 and 40 cm and they carry respectively 0.2 and 0.3 ampere current in opposite direction. The magnetic field in weber/m2 at the centre is

  • Physics-Moving Charges and Magnetism-83403.png
  • 2)
    Physics-Moving Charges and Magnetism-83404.png

  • Physics-Moving Charges and Magnetism-83405.png

  • Physics-Moving Charges and Magnetism-83406.png
If the strength of the magnetic field produced 10 cm away from a infinitely long straight conductor is 10–5 weber/m2, the value of the current flowing in the conductor will be
  • 5 ampere
  • 10 ampere
  • 500 ampere
  • 1000 ampere
A long solenoid of length L has a mean diameter D. It has n layers of windings 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
A closely wound flat circular coil of 25 turns of wire has diameter of 10 cm and carries a current of 4 ampere. Determine the flux density at the centre of a coil
  • 1.679 × 10–5 tesla
  • 2.028 × 10–4 tesla
  • 1.257 × 10–3 tesla
  • 1.512 × 10–6 tesla
1 A current flows through an infinitely long straight wire. The magnetic field produced at a point 1 metre away from it is
  • 2 × 10–3 tesla
  • 2/10 tesla
  • 2 × 10–7 tesla
  • 2π × 10–6 tesla
Two infinitely long parallel wires carry equal current in same direction. The magnetic field at a mid point in between the two wires is
  • Twice the magnetic field produced due to each of the wires
  • Half of the magnetic field produced due to each of the wires
  • Square of the magnetic field produced due to each of the wires
  • Zero
A wire in the form of a square of side \'a\' carries a current i. Then the magnetic induction at the centre of the square wire is (Magnetic permeability of free space = μ0)

  • Physics-Moving Charges and Magnetism-83414.png
  • 2)
    Physics-Moving Charges and Magnetism-83415.png

  • Physics-Moving Charges and Magnetism-83416.png

  • Physics-Moving Charges and Magnetism-83417.png
Circular loop of a wire and a long straight wire carry currents Ic and Ie, respectively as shown in figure. Assuming that these are placed in the same plane. The magnetic fields will be zero at the centre of the loop when the separation H is
Physics-Moving Charges and Magnetism-83419.png

  • Physics-Moving Charges and Magnetism-83420.png
  • 2)
    Physics-Moving Charges and Magnetism-83421.png

  • Physics-Moving Charges and Magnetism-83422.png

  • Physics-Moving Charges and Magnetism-83423.png
A long straight wire carries a current of π amp. The magnetic field due to it will be 5 × 10–5 weber/m2 at what distance from the wire [ μ0 = permeability of air]

  • Physics-Moving Charges and Magnetism-83425.png
  • 2)
    Physics-Moving Charges and Magnetism-83426.png

  • Physics-Moving Charges and Magnetism-83427.png

  • Physics-Moving Charges and Magnetism-83428.png
A long straight wire carrying current of 30 A is placed in an external uniform magnetic field of induction 4 × 10–4 T. The magnetic field is acting parallel to the direction of current. The magnitude of the resultant magnetic induction in tesla at a point 2.0 cm away from the wire is
  • 10–4
  • 3 × 10–4
  • 5 × 10–4
  • 6 × 10–4
A coil having N turns carry a current I as shown in the figure. The magnetic field intensity at point P is
Physics-Moving Charges and Magnetism-83431.png

  • Physics-Moving Charges and Magnetism-83432.png
  • 2)
    Physics-Moving Charges and Magnetism-83433.png

  • Physics-Moving Charges and Magnetism-83434.png
  • Zero
Two similar coils are kept mutually perpendicular such that their centres coincide. At the centre, find the ratio of the magnetic field due to one coil and the resultant magnetic field by both coils, if the same current is flown

  • Physics-Moving Charges and Magnetism-83435.png
  • 1 : 2
  • 2 : 1

  • Physics-Moving Charges and Magnetism-83436.png
A long wire carries a steady current. It is bent into a circle of one turn and the magnetic field at the centre of the coil is B. It is then bent into a circular loop of n turns. The magnetic field at the centre of the coil for same current will be
  • nB
  • n2B
  • 2nB
  • 2 n2B
The current is flowing in south direction along a power line. The direction of magnetic filed above the power line (neglecting earth\'s field) is
  • South
  • East
  • North
  • West
An electron is revolving round a proton, producing a magnetic field of 16 weber/m2 in a circular orbit of radius 1 Å. It\'s angular velocity will be

  • Physics-Moving Charges and Magnetism-83440.png
  • 2)
    Physics-Moving Charges and Magnetism-83441.png

  • Physics-Moving Charges and Magnetism-83442.png

  • Physics-Moving Charges and Magnetism-83443.png
A square conducting loop of side length L carries a current I. The magnetic field at the centre of the loop is
  • Independent of L
  • Proportional to L2
  • Inversely proportional to L
  • linearly proportional to L
A uniform electric field and a uniform magnetic field are produced, pointing in the same direction. If an electron is projected with its velocity pointing in the same direction
  • The electron will turn to its right
  • The electron will turn to its left
  • The electron velocity will increase in magnitude
  • The electron velocity will decrease in magnitude
Two particles X and Y having equal charges, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describe circular path of radius R1 and R2 respectively. The ratio of mass of X to that of Y is

  • Physics-Moving Charges and Magnetism-83447.png
  • 2)
    Physics-Moving Charges and Magnetism-83448.png

  • Physics-Moving Charges and Magnetism-83449.png

  • Physics-Moving Charges and Magnetism-83450.png
A charged particle moving in a magnetic field experiences a resultant force
  • In the direction of field
  • In the direction opposite to the field
  • In the direction perpendicular to both the field and its velocity
  • None of the above
If the direction of the initial velocity of the charged particle is perpendicular to the magnetic field, then the orbit will be
Or
The path executed by a charged particle whose motion is perpendicular to magnetic field is
  • A straight line
  • An ellipse
  • A circle
  • A helix
A 2 MeV proton is moving perpendicular to a uniform magnetic field of 2.5 tesla. The force on the proton is
  • 3 × 10–10 N
  • 8 × 10–11 N
  • 3 × 10–11 N
  • 8 × 10–12 N

Physics-Moving Charges and Magnetism-83454.png
  • Zero
  • –evB

  • Physics-Moving Charges and Magnetism-83455.png
  • None of these
A uniform magnetic field B is acting from south to north and is of magnitude 1.5 wb/m2. If a proton having mass = 1.7 × 10–27 kg and charge = 1.6 × 10–19C moves in this field vertically downwards with energy 5 MeV, then the force acting on it will be
  • 7.4 × 1012 N
  • 7.4 × 10–12 N
  • 7.4 × 1019 N
  • 7.4 × 10–19 N
The magnetic force on a charged particle moving in the field does not work, because
  • Kinetic energy of the charged particle does not change
  • The charge of the particle remains same
  • The magnetic force is parallel to velocity of the particle
  • The magnetic force is parallel to magnetic field
If a proton, deutron and α–particle on being accelerated by the same potential difference enters perpendicular to the magnetic field, then the ratio of their kinetic energies is
  • 1 : 2 : 2
  • 2 : 2 : 1
  • 1 : 2 : 1
  • 1 : 1 : 2
A proton (or charged particle) moving with velocity v is acted upon by electric field E and magnetic field B. The proton will move undeflected if
  • E is perpendicular to B
  • E is parallel to v and perpendicular to B
  • E, B and v are mutually perpendicular and v = E/B
  • E and B both are parallel to v
An electron is moving on a circular path of radius r with speed v in a transverse magnetic field B. e/m for it will be

  • Physics-Moving Charges and Magnetism-83460.png
  • 2)
    Physics-Moving Charges and Magnetism-83461.png
  • Bvr

  • Physics-Moving Charges and Magnetism-83462.png
An electron enters a magnetic field whose direction is perpendicular to the velocity of the electron. Then
  • The speed of the electron will increase
  • The speed of the electron will decrease
  • The speed of the electron will remain the same
  • The velocity of the electron will remain the same

Physics-Moving Charges and Magnetism-83466.png
  • Zero
  • 2)
    Physics-Moving Charges and Magnetism-83467.png

  • Physics-Moving Charges and Magnetism-83468.png
  • None of these
A proton moving with a velocity 2.5 × 107 m/s, enters a magnetic field of intensity 2.5 T making an angle 30° with the magnetic field. The force on the proton is
  • 3 × 10–12 N
  • 5 × 10–12 N
  • 6 × 10–12 N
  • 9 × 10–12 N
A beam of electrons passes undeflected through mutually perpendicular electric and magnetic fields. If the electric field is switched off and the same magnetic field is maintained, the electrons move
  • In an elliptical orbit
  • In a circular orbit
  • Along a parabolic path
  • Along a straight line

Physics-Moving Charges and Magnetism-83472.png
  • +ve z–axis, –ve x-axis, +ve y–axis
  • –ve z–axis, –ve x–axis and zero
  • +ve z–axis, +ve y–axis and zero
  • –ve z–axis, +ve x–axis and zero
An electron of mass m and charge q is travelling with a speed v along a circular path of radius r at right angles to a uniform of magnetic field B. If speed of the electron is doubled and the magnetic field is halved, then resulting path would have a radius of
  • r/4
  • r/2
  • 2r
  • 4r
A uniform electric field and a uniform magnetic field exist in a region in the same direction. An electron is projected with a velocity in the same direction. Then the electron will
  • Be deflected to the left without increase in speed
  • Be deflected to the right without increase in speed
  • Not be deflected but its speed will decrease
  • Not be deflected but its speed will increase
A particle of mass m and charge q enters a magnetic field B perpendicularly with a velocity v. The radius of the circular path described by it will be

  • Physics-Moving Charges and Magnetism-83474.png
  • 2)
    Physics-Moving Charges and Magnetism-83475.png

  • Physics-Moving Charges and Magnetism-83476.png

  • Physics-Moving Charges and Magnetism-83477.png
The radius of circular path of an electron when subjected to a perpendicular magnetic field is

  • Physics-Moving Charges and Magnetism-83478.png
  • 2)
    Physics-Moving Charges and Magnetism-83479.png

  • Physics-Moving Charges and Magnetism-83480.png

  • Physics-Moving Charges and Magnetism-83481.png
An α particle and a proton travel with same velocity in a magnetic field perpendicular to the direction of their velocities. Find the ratio of the radii of their circular path
  • 4 : 1
  • 1 : 4
  • 2 : 1
  • 1 : 2
An electron (mass = 9 × 10–31 kg, charge = 1.6 × 10–19 C) whose kinetic energy is 7.2 × 10–18 joule is moving in a circular orbit in a magnetic field of 9 × 10–5 weber/m2. The radius of the orbit is
  • 1.25 cm
  • 2.5 cm
  • 12.5 cm
  • 25.0 cm
An electron enters a region where electrostatic field is 20 N/C and magnetic field is 5 T. If electron passes undeflected through the region, then velocity of electron will be
  • 0.25 ms–1
  • 2 ms–1
  • 4 ms–1
  • 8 ms–1
In the given figure, the electron enters into the magnetic field. It deflects in ……. direction
Physics-Moving Charges and Magnetism-83486.png
  • +ve X direction
  • –ve X direction
  • +ve Y direction
  • –ve Y direction

Physics-Moving Charges and Magnetism-83487.png
  • Opposite to OX
  • Along OX
  • Opposite to OY
  • Along OY
A cyclotron is used to accelerate protons, deuterons, α–particles etc. If the energy attained, after acceleration, by the protons is E, the energy attained by α–particles shall
  • 4E
  • 2E
  • E
  • E/4

Physics-Moving Charges and Magnetism-83494.png
  • Its charge
  • Magnetic field
  • Speed
  • None of these
An electron revolves in a circle of radius 0.4 Å with a speed of 105 ms–1. The magnitude of the magnetic field, produced at the centre of the circular path due to the motion of the electron, in weber metre–2 is
  • 0.01
  • 10.0
  • 1.0
  • 0.005
An electron rotates about a proton, the induced magnetic field is 14 T at the centre, find out the angular velocity of electron if radius of rotation is 0.5 nm
  • 4.4 × 1017 rad/sec
  • 4.4 × 1012 rad/sec
  • 3.14 × 10–15 rad/sec
  • 4.2 × 1010 rad/sec
A charged particle (charge q) is moving in a circle of radius R with uniform speed v. The associated magnetic moment μ is given by

  • Physics-Moving Charges and Magnetism-83498.png
  • 2)
    Physics-Moving Charges and Magnetism-83499.png

  • Physics-Moving Charges and Magnetism-83500.png

  • Physics-Moving Charges and Magnetism-83501.png
The magnitude of the magnetic field required to accelerate protons (mass = 1.67 × 10–27 kg) in a cyclotron that is operated at an oscillator frequency 12 MHz is approximately
  • 0.8 T
  • 1.6 T
  • 2.0 T
  • 3.2 T
Two particles A and B having equal charges +6 C, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describe circular paths of radii 2 cm and 3 cm respectively. The ratio of mass to A to that of B is
  • 4/9
  • 9/5
  • 1/2
  • 1/3
  • 9/4
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Physics Quiz Questions and Answers