Physics - Magnetism Question with Solution | TestHub

PhysicsMagnetismBiot-savart's & Ampere's Circuital lawEasy2 minPYQ_2020

PhysicsEasysingle choice

A wire is tightly wound to form of a spiral of $N$ turns with the inner and outer radii equal to $a$ and $b$ respectively. When a current $I$ is established in the coil, the magnetic field at the centre is

Options:

Answer:

Solution:

An element is assumed at distance $x$ from center whose width is $d x$ . No. of turns in width $b - a = N$

$∴$ No. of turns is width $d x = n = (\frac{N}{b - a}) d x$

$d B = \frac{μ_{0} n i}{2 x} = \frac{μ_{0} i N}{2 (b - a)} \frac{d x}{x} ∴ B = \frac{μ_{0} i N}{2 (b - a)} \int_{a}^{b} \frac{d x}{x} = \frac{μ_{0} N i}{2 (b - a)} \log_{e} (\frac{b}{a})$

Subject:PhysicsTopic:MagnetismSubtopic:Biot-savart's & Ampere's Circuital law

⏱ 2mℹ️ Source: PYQ_2020

Doubts & Discussion

Loading discussions...