Question

A toroid has a core (non-ferromagnetic material) of inner radius $25\text{cm}$ and outer radius $26\text{cm}$ around which $3500$ turns of wire are wound. If the current in the wire is $11\text{A}$, what is the magnetic field outside the toroid ?

• A. $3\times {10}^{-2}\text{T}$
• B. $1\times {10}^{-2}\text{T}$
• C. $3\times {10}^{-5}\text{T}$
• D. zero

Answer 1

The correct option is D zero

The magnetic field outside the toroid remains $0$.