Q.1
A galvanometer of 50 Ω resistance has 25 divisions. A current of 4×10⁻⁴ ampere gives a deflection of one per division. To convert this galvanometer into voltmeter having a range of 25 volts, it should be connected with a resistance of ... [ CBSE-PMT 2004]
  • a) 2450 Ω in series
  • b) 2500 Ω
  • c) 245 Ω
  • d) 2550 Ω
Q.2
Two straight parallel wires both carrying 1 amp current in the same direction attracts each other with a force of 1×10⁻³ N. If both the currents are doubled, the force of attraction will be [ MPPMT 1994]
  • a)1×10⁻³ N
  • b) 2×10⁻³ N
  • c)4×10⁻³ N
  • d)0.25×10⁻³ N
Q.3
A particle with 10-11 coulomb charge and 10-7 kg mass is moving with velocity of 108 m/s along the y-axis. A uniform static magnetic field B=0.5 Tesla is acting along x-direction. The force on the particle is [ MPPMT 1997]
  • b) 5×103 N along k
  • a)5×10⁻¹¹ N along i
  • c)5×10⁻¹¹ N along -j
  • d)5×10⁻⁴ N along -k
Q.4
A coil of 100 turns and area 5 square centimetre is placed in a magnetic field B=0.2T. The normal to the plane of the coil makes angle of 60° with the direction of the magnetic field. The magnetic flux linked with the coil is [ MPPMT 1997]
  • c) 10-2 Wb
  • d) 10-4 Wb
  • a) 5×10⁻³ Wb
  • b) 5×10⁻⁵ Wb
Q.5
A proton enters a magnetic field of flux density 1.5 weber/metre2 with a velocity of 2×104 metre / sec at an angle of 30° with the field. The force on the proton will be [ MPPMT 1994]
  • a) 2.4×10⁻¹² N
  • b) 0.24×10⁻¹² N
  • c) 24×10⁻¹² N
  • d) 0.024×10⁻¹² N
Q.6
In the hydrogen atom, the electron revolves in circular orbit of radius 0.53×10⁻¹⁰ metre and makes 6.6×1015 r.p.s. Then the magnetic dipole moment is approximately [ MPPMT 1999]
  • a)10-29 amp×metre2
  • b) 10-27 amp×metre2
  • c)10-23 amp×metre2
  • d)10-19 amp×metre2
Q.7
A conductor in the form of right angle ABC, with AB=3 cm and BC=4 cm, carries a current of 10A. There is uniform magnetic field of 5T, perpendicular to the plane of the conductor. The force on the conductor AC will be [ MPPMT 1997]
ch-16_que_no-160_img_no1.png
  • a) 1.5 N
  • b) 2.0 N
  • c) 2.5 N
  • d) 3.5 N
Q.8
A current of 5 ampere is passed through a straight wire of length 6cms then the magnetic induction at a point 5cms from either end of the wire is
  • a) 0.25 gauss
  • b) 0.12 gauss
  • c)0.15 gauss
  • d)0.30 gauss
Q.9
A circular coil of 50 turns carries a current of 0.2A. The earth's magnetic field is 6×10⁻⁵ T. the net field at the centre of coil is zero. The radius of the coil is
  • a)1.047 cm
  • b) 10.47 cm
  • c)1.047 m
  • d)10.47 m
Q.10
A circular coil of radius 4 cm having 5 turns carries a current of 2A. It is placed in uniform magnetic field of intensity 0.1 weber/mThe work done to rotate the coil from the equilibrium position through 180° is
  • a) 0.1 J
  • b) 0.2 J
  • c)0.4 J
  • d)0.8 J
Q.11
The plane of a rectangular loop of wire with sides 0.05 m and 0.08 m is parallel to a uniform magnetic field of induction 1.5×10⁻² tesla. A current of 10.0 amp. flows through the loop. If the side of length 0.08 m in normal and the side of length 0.05 m is parallel to the line of induction, then torque acting on it is
  • a) 6000 Newton × metre
  • b) Zero
  • c) 1.2 × 10⁻² newton × metre
  • d) 6 × 10⁻⁴ newton × metre
Q.12
A beam of ion with velocity 2 ×105 m/s, enters perpendicularly to a uniform magnetic field of 4 ×10⁻² Tesla. If the specific charge of the ion is 5 ×10⁻⁷ C/ kg, the radius of the circular path will be ....
  • a)0.1 m
  • b) 0.16 m
  • c)0.2 m
  • d)0.25 m
Q.13
A long starlight wire carrying a current of 30A 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 2cm away from wire is .....
  • a)10-4
  • b) 3 × 10⁻⁴
  • c)5 × 10⁻⁴
  • d)6 × 10⁻⁴
Q.14
A long solenoid has 1000 turns. When a current of 4A flows through it, the magnetic flux linked with each turn of the solenoid is 4×10⁻³Wb. The self inductance of the solenoid is
  • a) 4H
  • b) 3H
  • c) 2H
  • d) 1H
Q.15
A 250-Turn rectangular coil of length 2.1 cm andwidth 1.25 cm carries a current of 85 μA and subjected to a magnetic field of strength 0.85 T.Work done for rotating the coil by 180° against the torque is [ NEET 207]
  • a) 9.1 µJ
  • b) 4.55 µJ
  • c) 2.3 µJ
  • d) 1.15 µJ
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