CLASS : XII
SUBJECT : PHYSICS
CHAPTER-04-MOVING CHARGE AND MAGNETISM
ONE MARKS: (5)
1. What is the direction of the force acting on a charged particle q, moving with a velocity in a uniform magnetic
field B?
2. An electron does not suffer any deflection while passing through a region of uniform magnetic field. What is the
direction of the magnetic field?
3. A beam of protons, projected along + x-axis, experiences a force due to a magnetic field along the – y-axis.
What is the direction of the magnetic field?
4. Depict the trajectory of a charged particle moving with velocity v as it enters a uniform magnetic field
perpendicular to the direction of its motion.
5. Write the condition under which an electron will move un deflected in the presence of crossed electric and
magnetic fields.
2 MARKS ANY 4 (8)
1. An ammeter of resistance 0.6 Ω can measure current up to 1.0 A. Calculate
(i) The shunt resistance required to enable the ammeter to measure current up to 5.0 A
(ii) The combined resistance of the ammeter and the shunt.
2. Using Ampere’s circuital law, obtain an expression for the magnetic field along the axis of a current carrying
solenoid of length l and having N number of turns.
3. A current I flows in a conductor placed perpendicular to the plane of the paper. Indicate the direction of the
magnetic field due to a small element dl at point P situated at a distance r from the element as
4. A steady current (I1) flows through a long straight wire. Another wire carrying steady current (I2) in the same
direction is kept close and parallel to the first wire. Show with the help of a diagram how the magnetic field due to
the current I1 exerts a magnetic force on the second wire. Write the expression for this force
5. A circular coil of closely wound N turns and radius r carries a current I. Write the expressions for the following :
(i) the magnetic field at its centre
(ii) the magnetic moment of this coil
3 marks. (15)
1. A particle of mass 10-3 kg and charge 5 pC enters into a uniform electric field of 2 × 105 NC-1, moving with a
velocity of 20 ms-1 in a direction opposite to that of the field. Calculate the distance it would travel before coming to
rest.
2. An ammeter of resistance 0.80 Ω can measure current upto 1.0 A.
(i) What must be the value of shunt resistance to enable the ammeter to measure current upto 5.0A?
(ii) What is the combined resistance of the ammeter and the shunt?
3. A rectangular coil of sides ‘V and ‘b’ carrying a current I is subjected to a uniform magnetic field acting
perpendicular to its plane. Obtain the expression for the torque acting on it.
4. Write the expression for the magnitude of the magnetic field at the centre of a circular loop of radius r carrying a
steady current I. Draw the field lines due to the current loop.
5. A charge q of mass m is moving with a velocity of v, at right angles to a uniform magnetic field B. Deduce the
expression for the radius of the circular path it describes.
5 MARKS ANY (3) (20)
1
SUBJECT : PHYSICS
CHAPTER-04-MOVING CHARGE AND MAGNETISM
ONE MARKS: (5)
1. What is the direction of the force acting on a charged particle q, moving with a velocity in a uniform magnetic
field B?
2. An electron does not suffer any deflection while passing through a region of uniform magnetic field. What is the
direction of the magnetic field?
3. A beam of protons, projected along + x-axis, experiences a force due to a magnetic field along the – y-axis.
What is the direction of the magnetic field?
4. Depict the trajectory of a charged particle moving with velocity v as it enters a uniform magnetic field
perpendicular to the direction of its motion.
5. Write the condition under which an electron will move un deflected in the presence of crossed electric and
magnetic fields.
2 MARKS ANY 4 (8)
1. An ammeter of resistance 0.6 Ω can measure current up to 1.0 A. Calculate
(i) The shunt resistance required to enable the ammeter to measure current up to 5.0 A
(ii) The combined resistance of the ammeter and the shunt.
2. Using Ampere’s circuital law, obtain an expression for the magnetic field along the axis of a current carrying
solenoid of length l and having N number of turns.
3. A current I flows in a conductor placed perpendicular to the plane of the paper. Indicate the direction of the
magnetic field due to a small element dl at point P situated at a distance r from the element as
4. A steady current (I1) flows through a long straight wire. Another wire carrying steady current (I2) in the same
direction is kept close and parallel to the first wire. Show with the help of a diagram how the magnetic field due to
the current I1 exerts a magnetic force on the second wire. Write the expression for this force
5. A circular coil of closely wound N turns and radius r carries a current I. Write the expressions for the following :
(i) the magnetic field at its centre
(ii) the magnetic moment of this coil
3 marks. (15)
1. A particle of mass 10-3 kg and charge 5 pC enters into a uniform electric field of 2 × 105 NC-1, moving with a
velocity of 20 ms-1 in a direction opposite to that of the field. Calculate the distance it would travel before coming to
rest.
2. An ammeter of resistance 0.80 Ω can measure current upto 1.0 A.
(i) What must be the value of shunt resistance to enable the ammeter to measure current upto 5.0A?
(ii) What is the combined resistance of the ammeter and the shunt?
3. A rectangular coil of sides ‘V and ‘b’ carrying a current I is subjected to a uniform magnetic field acting
perpendicular to its plane. Obtain the expression for the torque acting on it.
4. Write the expression for the magnitude of the magnetic field at the centre of a circular loop of radius r carrying a
steady current I. Draw the field lines due to the current loop.
5. A charge q of mass m is moving with a velocity of v, at right angles to a uniform magnetic field B. Deduce the
expression for the radius of the circular path it describes.
5 MARKS ANY (3) (20)
1
