Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
MHT CET202410 May 2024Evening ShiftPhysicsMagnetic Effects of CurrentActual

A coil of ' n ' turns and radius ' R ' carries a current 'I'. It is unwound and rewound to make a new coil of radius R 3 and the same current is passed through it. The ratio of the magnetic moment of the new coil to that of the original coil is

Options

  1. A3
  2. B2
  3. C1 3
  4. D1 2

Correct answer

C. 1 3

Step-by-step solution

Let the initial magnetic moment be ₁=n₁ I A₁= n ₁ I R ₁ ^2 And, the final magnetic moment ₂= n ₂ I R ₂^2 Given, R ₁= R , R ₂= R 3 , n ₂=3 n ₁ ₂ ₁ = n ₂ n ₁ ( R ₂ R ₁ )^2=3 ( 1 3 )^2= 1 3

Practice Magnetic Effects of Current on Quantrex Academy →

More from Magnetic Effects of Current

The current through the circular coil is halved and the radius of the coil is doubled. If B₁ and B₂ are respectively the initial and final magnetic field strength, then: 2026A circular coil of radius r = 10 ,cm having 300 turns carries a current of 2A. The coil is suspended vertically in a uniform magnetic field of strength 0.7 T. If the plane of the c 2026Two long parallel conductors X and Y are placed vertically at a distance d apart. Conductor X carries a current I upwards and conductor Y carries a current 2I downwards. A third lo 2026A proton is moving along negative X axis. If a uniform magnetic field is applied parallel to the positive Z axis, then choose the correct answer from the following options; 1. The 2026The magnetic field at the centre of a wire loop formed by two semicircular wires of radii r₁ = 3.14m and r₂ = 6.28m and carrying a current of I =2A is: 2026If a wire of length ' L ' carrying a current ' i ' is bent in the shape of a semi-circular arc as shown in the figure, then the magnetic field at centre of the arc is 2025If a current of 15 A passes through a solenoid of length 25 cm, radius 2 cm and number of turns 500, then the magnetic moment of the solenoid is 2025The maximum magnetic field produced by a current of 12 A passing through a copper wire of diameter 1.2 mm is 2025 Full Magnetic Effects of Current list All MHT CET PYQs