DPP - Daily Practice Problems
Chapter-wise Sheets
Date : Start Time : End Time :
PHYSICS CP18
SYLLABUS : Moving Charges and Magnetism
Max. Marks : 180 Marking Scheme : (+4) for correct & (–1) for incorrect answer Time : 60 min.
INSTRUCTIONS : This Daily Practice Problem Sheet contains 45 MCQs. For each question only one option is correct.
Darken the correct circle/ bubble in the Response Grid provided on each page.
1. An insulating rod of length l carries a charge q distributed 5 × 10–2 tesla making an angle of 30° with the axis of the
uniformly on it. The rod is pivoted at its mid point and is solenoid. The torque on the solenoid will be:
rotated at a frequency f about a fixed axis perpendicular to (a) 3 × 10–2 N-m (b) 3 × 10–3 N-m
–3
(c) 1.5 × 10 N-m (d) 1.5 × 10–2 N-m
rod and passing through the pivot. The magnetic moment
4. An alternating electric field, of frequency v, is applied across
1
of the rod system is pqfl 2 . Find the value of a. the dees (radius = R) of a cyclotron that is being used to
2a accelerate protons (mass = m). The operating magnetic field
(a) 6 (b) 4 (B) used in the cyclotron and the kinetic energy (K) of the
(c) 5 (d) 8 proton beam, produced by it, are given by :
2. A portion of a conductive wire is bent in the form of a (a) B = mn and K = 2mp2n2R2
semicircle of radius r as shown below in fig. At the centre of e
semicircle, the magnetic induction will be (b) B = pmn and K = m2pnR2
2
e
(c) B = mn and K = 2mp2n2R2
2 p
i
r
e
i
O mn
(d) B = and K = m2pnR2
e
(a) zero (b) infinite 5. A galvanometer of 50 ohm resistance has 25 divisions. A
μ 0 2π i μ0 π i current of 4 × 10–4 ampere gives a deflection of one per
(c) 4 π . r (d) 4 π . r division. To convert this galvanometer into a voltmeter
3. A closely wound solenoid of 2000 turns and area of cross- having a range of 25 volts, it should be connected with a
section 1.5 × 10–4 m2 carries a current of 2.0 A. It suspended resistance of
through its centre and perpendicular to its length, allowing (a) 2450 W in series (b) 2500 W in series.
it to turn in a horizontal plane in a uniform magnetic field (c) 245 W in series. (d) 2550 W in series.
RESPONSE GRID 1. 2. 3. 4. 5.
Space for Rough Work
, P-70 DPP/ CP18
6. If we double the radius of a coil keeping the current through r r
(a) 3 F (b) – F
it unchanged, then the magnetic field at any point at a large r r
distance from the centre becomes approximately (c) – 3 F (d) F
(a) double (b) three times 15. A straight section PQ of a circuit lies along the X-axis from
(c) four times (d) one-fourth a a
7. A particle of mass m, charge Q and kinetic energy T enters a x = - to x = and carries a steady current i. The
r 2 2
transverse uniform magnetic field of induction B . After 3 magnetic field due to the section PQ at a point X = + a will be
seconds, the kinetic energy of the particle will be: (a) proportional to a (b) proportional to a2
(a) 3T (b) 2T (c) proportional to 1/a (d) zero
(c) T (d) 4T 16. A and B are two A
8. A 10 eV electron is circulating in a plane at right angles to a conductors carrying a
uniform field at magnetic induction 10–4 Wb/m2 (= 1.0 current i in the same
gauss). The orbital radius of the electron is direction. x and y are B
(a) 12 cm (b) 16 cm two electron beams
moving in the same x
(c) 11 cm (d) 18 cm
direction. Then
9. A uniform electric field and a uniform magnetic field exist in y
a region in the same direction. An electron is projected with (a) there will be repulsion betwen A and B, attraction between
velocity pointed in the same direction. The electron will x and y
(a) turn to its right (b) there will be attraction between A and B, repulsion
(b) turn to its left between x and y
(c) keep moving in the same direction but its speed will (c) there will be repulsion between A and B and also x and y
increase (d) there will be attraction between A and B and also x and y
(d) keep moving in the same direction but its speed will 17. A galvanometer of resistance, G is shunted by a resistance
decrease S ohm. To keep the main current in the circuit unchanged,
10. Proton, deuteron and alpha particle of same kinetic energy the resistance to be put in series with the galvanometer is
are moving in circular trajectories in a constant magnetic S2 SG G2 G
field. The radii of proton, deuteron and alpha particle are (a) (b) (c) (d)
(S + G) (S + G) (S + G) (S + G)
respectively rp, rd and ra. Which one of the following relation 18. A current I flows in an infinitely long wire with cross section
is correct? in the form of a semi-circular ring of radius R. The magnitude
(a) ra = rp = rd (b) ra = rp < rd of the magnetic induction along its axis is:
m0 I m0 I m0 I m0 I
(c) ra > rd > rp (d) ra = rd > rp (a) 2
2p R
(b)
2pR
(c)
4pR
(d) 2
Ip R
11. A moving coil galvanometer has 150 equal divisions. Its 19. Two equal electric currents are flowing
perpendicular to each other as shown C A
current sensitivity is 10-divisions per milliampere and voltage
sensitivity is 2 divisions per millivolt. In order that each in the figure. AB and CD are
division reads 1 volt, the resistance in ohms needed to be perpendicular to each other and O
symmetrically placed with respect to I
connected in series with the coil will be
the current flow. Where do we expect
(a) 105 (b) 103 (c) 9995 (d) 99995 the resultant magnetic field to be zero?
12. A 2 µC charge moving around a circle with a frequency of B D
6.25 × 1012 Hz produces a magnetic field 6.28 tesla at the
centre of the circle. The radius of the circle is (a) On AB (b) On CD
(a) 2.25 m (b) 0.25 m (c) 13.0 m (d) 1.25 m (c) On both AB and CD (d) On both OD and BO
13. A charged particle with charge q enters a region
ur ofuconstant,
r 20. A closed loop PQRS carrying a current is placed in a uniform
uniform and mutually orthogonalurfields uE and B with a magnetic field.
r r If the magnetic forces on segments PS, Q
velocity v perpendicular to both E and B , and comes out
r SR, and RQ are F1 , F2 and F3 respectively
without any change in magnitude or direction of v . Then
r ur ur r ur ur and are in the plane of the paper and along P
(a) v = B ´ E / E 2 (b) v = E ´ B / B 2 the directions shown, the force on the
r ur ur 2 r ur ur segment QP is F3
(c) v = B ´ E / B (d) v = E ´ B / E 2 (a) F3 – F1– F2 F1
14. A square current carrying loop is suspended in a uniform
magnetic field acting in the
r plane of the loop. If the force on (b) (F3 – F1 )2 + F22
one arm of the loop is F , the net force on the remaining S R
three arms of the loop is
(c) (F3 – F1 ) – F22
2
F2
(d) F3 – F1+F2
6. 7. 8. 9. 10.
RESPONSE
11. 12. 13. 14. 15.
GRID 16. 17. 18. 19. 20.
Space for Rough Work
Chapter-wise Sheets
Date : Start Time : End Time :
PHYSICS CP18
SYLLABUS : Moving Charges and Magnetism
Max. Marks : 180 Marking Scheme : (+4) for correct & (–1) for incorrect answer Time : 60 min.
INSTRUCTIONS : This Daily Practice Problem Sheet contains 45 MCQs. For each question only one option is correct.
Darken the correct circle/ bubble in the Response Grid provided on each page.
1. An insulating rod of length l carries a charge q distributed 5 × 10–2 tesla making an angle of 30° with the axis of the
uniformly on it. The rod is pivoted at its mid point and is solenoid. The torque on the solenoid will be:
rotated at a frequency f about a fixed axis perpendicular to (a) 3 × 10–2 N-m (b) 3 × 10–3 N-m
–3
(c) 1.5 × 10 N-m (d) 1.5 × 10–2 N-m
rod and passing through the pivot. The magnetic moment
4. An alternating electric field, of frequency v, is applied across
1
of the rod system is pqfl 2 . Find the value of a. the dees (radius = R) of a cyclotron that is being used to
2a accelerate protons (mass = m). The operating magnetic field
(a) 6 (b) 4 (B) used in the cyclotron and the kinetic energy (K) of the
(c) 5 (d) 8 proton beam, produced by it, are given by :
2. A portion of a conductive wire is bent in the form of a (a) B = mn and K = 2mp2n2R2
semicircle of radius r as shown below in fig. At the centre of e
semicircle, the magnetic induction will be (b) B = pmn and K = m2pnR2
2
e
(c) B = mn and K = 2mp2n2R2
2 p
i
r
e
i
O mn
(d) B = and K = m2pnR2
e
(a) zero (b) infinite 5. A galvanometer of 50 ohm resistance has 25 divisions. A
μ 0 2π i μ0 π i current of 4 × 10–4 ampere gives a deflection of one per
(c) 4 π . r (d) 4 π . r division. To convert this galvanometer into a voltmeter
3. A closely wound solenoid of 2000 turns and area of cross- having a range of 25 volts, it should be connected with a
section 1.5 × 10–4 m2 carries a current of 2.0 A. It suspended resistance of
through its centre and perpendicular to its length, allowing (a) 2450 W in series (b) 2500 W in series.
it to turn in a horizontal plane in a uniform magnetic field (c) 245 W in series. (d) 2550 W in series.
RESPONSE GRID 1. 2. 3. 4. 5.
Space for Rough Work
, P-70 DPP/ CP18
6. If we double the radius of a coil keeping the current through r r
(a) 3 F (b) – F
it unchanged, then the magnetic field at any point at a large r r
distance from the centre becomes approximately (c) – 3 F (d) F
(a) double (b) three times 15. A straight section PQ of a circuit lies along the X-axis from
(c) four times (d) one-fourth a a
7. A particle of mass m, charge Q and kinetic energy T enters a x = - to x = and carries a steady current i. The
r 2 2
transverse uniform magnetic field of induction B . After 3 magnetic field due to the section PQ at a point X = + a will be
seconds, the kinetic energy of the particle will be: (a) proportional to a (b) proportional to a2
(a) 3T (b) 2T (c) proportional to 1/a (d) zero
(c) T (d) 4T 16. A and B are two A
8. A 10 eV electron is circulating in a plane at right angles to a conductors carrying a
uniform field at magnetic induction 10–4 Wb/m2 (= 1.0 current i in the same
gauss). The orbital radius of the electron is direction. x and y are B
(a) 12 cm (b) 16 cm two electron beams
moving in the same x
(c) 11 cm (d) 18 cm
direction. Then
9. A uniform electric field and a uniform magnetic field exist in y
a region in the same direction. An electron is projected with (a) there will be repulsion betwen A and B, attraction between
velocity pointed in the same direction. The electron will x and y
(a) turn to its right (b) there will be attraction between A and B, repulsion
(b) turn to its left between x and y
(c) keep moving in the same direction but its speed will (c) there will be repulsion between A and B and also x and y
increase (d) there will be attraction between A and B and also x and y
(d) keep moving in the same direction but its speed will 17. A galvanometer of resistance, G is shunted by a resistance
decrease S ohm. To keep the main current in the circuit unchanged,
10. Proton, deuteron and alpha particle of same kinetic energy the resistance to be put in series with the galvanometer is
are moving in circular trajectories in a constant magnetic S2 SG G2 G
field. The radii of proton, deuteron and alpha particle are (a) (b) (c) (d)
(S + G) (S + G) (S + G) (S + G)
respectively rp, rd and ra. Which one of the following relation 18. A current I flows in an infinitely long wire with cross section
is correct? in the form of a semi-circular ring of radius R. The magnitude
(a) ra = rp = rd (b) ra = rp < rd of the magnetic induction along its axis is:
m0 I m0 I m0 I m0 I
(c) ra > rd > rp (d) ra = rd > rp (a) 2
2p R
(b)
2pR
(c)
4pR
(d) 2
Ip R
11. A moving coil galvanometer has 150 equal divisions. Its 19. Two equal electric currents are flowing
perpendicular to each other as shown C A
current sensitivity is 10-divisions per milliampere and voltage
sensitivity is 2 divisions per millivolt. In order that each in the figure. AB and CD are
division reads 1 volt, the resistance in ohms needed to be perpendicular to each other and O
symmetrically placed with respect to I
connected in series with the coil will be
the current flow. Where do we expect
(a) 105 (b) 103 (c) 9995 (d) 99995 the resultant magnetic field to be zero?
12. A 2 µC charge moving around a circle with a frequency of B D
6.25 × 1012 Hz produces a magnetic field 6.28 tesla at the
centre of the circle. The radius of the circle is (a) On AB (b) On CD
(a) 2.25 m (b) 0.25 m (c) 13.0 m (d) 1.25 m (c) On both AB and CD (d) On both OD and BO
13. A charged particle with charge q enters a region
ur ofuconstant,
r 20. A closed loop PQRS carrying a current is placed in a uniform
uniform and mutually orthogonalurfields uE and B with a magnetic field.
r r If the magnetic forces on segments PS, Q
velocity v perpendicular to both E and B , and comes out
r SR, and RQ are F1 , F2 and F3 respectively
without any change in magnitude or direction of v . Then
r ur ur r ur ur and are in the plane of the paper and along P
(a) v = B ´ E / E 2 (b) v = E ´ B / B 2 the directions shown, the force on the
r ur ur 2 r ur ur segment QP is F3
(c) v = B ´ E / B (d) v = E ´ B / E 2 (a) F3 – F1– F2 F1
14. A square current carrying loop is suspended in a uniform
magnetic field acting in the
r plane of the loop. If the force on (b) (F3 – F1 )2 + F22
one arm of the loop is F , the net force on the remaining S R
three arms of the loop is
(c) (F3 – F1 ) – F22
2
F2
(d) F3 – F1+F2
6. 7. 8. 9. 10.
RESPONSE
11. 12. 13. 14. 15.
GRID 16. 17. 18. 19. 20.
Space for Rough Work
