Physics Circle home Student Login

Home›Chapters›Moving Charges and Magnetism PYQs›Ampere's Law, Cylinders, Solenoid & Toroid›Question 56

JEE Main 2007 (AIEEE) · Ampere's Law, Cylinders, Solenoid & Toroid

Ampere's Law, Cylinders, Solenoid & Toroid question from JEE Main 2007 (AIEEE)

Q56JEE Main 2007 · AIEEEEasy

Ampere's Law, Cylinders, Solenoid & Toroid

A long straight wire of radius aa carries a steady current i.i. The current is uniformly distributed across its cross section. The ratio of the magnetic field at a/2a/2 and 2a2a is

Show answer and solution

Answer: (d)

  1. At a/2a/2: B1=μ0i(a/2)2πa2=μ0i4πaB_1 = \dfrac{\mu_0 i (a/2)}{2\pi a^2} = \dfrac{\mu_0 i}{4\pi a}.
  2. At 2a2a: B2=μ0i2π(2a)=μ0i4πaB_2 = \dfrac{\mu_0 i}{2\pi (2a)} = \dfrac{\mu_0 i}{4\pi a}.
  3. So the answer is (d) 11.
Report a mistake

More questions on Ampere's Law, Cylinders, Solenoid & Toroid