Student Login

Home›Chapters›Moving Charges and Magnetism PYQs›Biot-Savart Law & Circular Coils›Question 38

MHT CET 2024 (15 May, Shift 2) · Biot-Savart Law & Circular Coils

Biot-Savart Law & Circular Coils question from MHT CET 2024 (15 May, Shift 2)

Q38MHT CET 2024 · 15 MAY · SHIFT 2Easy

Biot-Savart Law & Circular Coils

Two concentric circular coils A and B having radii 20 cm and 10 cm respectively lie in the same plane. The current in coil A is 0.5 A in anticlockwise direction. The current in coil B, so that net magnetic field at the common centre is zero, is

Show answer and solution

Answer: (c)

For zero net field: $\frac{\mu_0 I_A}{2r_A} = \frac{\mu_0 I_B}{2r_B}$ , with fields opposite.
$I_B = I_A\frac{r_B}{r_A} = 0.5\times\frac{10}{20} = 0.25\text{ A}$
Opposite field needs opposite current, i.e. clockwise.
So the answer is (c) 0.25 A clockwise.

Report a mistake

More questions on Biot-Savart Law & Circular Coils

Two identical current carrying coils with same centre are placed with their planes…MHT CET 2024 (2 May, Shift 1)
An element Δ l = Δ x i is placed at the origin and carries a large current I = 10 A. The…JEE Main 2024 (6 Apr, Shift 1)
A thin ring of radius ' R ' carries a uniformly distributed charge. The ring rotates at…MHT CET 2024 (3 May, Shift 2)
A particle having a charge 50 e is revolving in a circular path of radius 0.4 m with 1…MHT CET 2024 (3 May, Shift 1)
The magnetic field at the centre of a wire loop formed by two semicircular wires of radii…JEE Main 2024 (27 Jan, Shift 2)
Two insulated circular loops A and B of radius ' a ' carrying a current of ' I ' in the…JEE Main 2024 (30 Jan, Shift 1)
Two circular coils P and Q of 100 turns each have same radius of π cm. The currents in P…JEE Main 2024 (31 Jan, Shift 2)
The magnetic field at the centre of a circular coil of radius ' R ', carrying current 2A…MHT CET 2023 (10 May, Shift 2)