JEE Advanced 2018 · Paper 1 · Physics Q16

← JEE Advanced 2018 · Paper 1

PhysicsSingle correct+3 / -1Question 16 of 54

Passage

PARAGRAPH “X”

In electromagnetic theory, the electric and magnetic phenomena are related to each other. Therefore, the dimensions of electric and magnetic quantities must also be related to each other. In the questions below, $[E]$ and $[B]$ stand for dimensions of electric and magnetic fields respectively, while $[\epsilon_0]$ and $[\mu_0]$ stand for dimensions of the permittivity and permeability of free space respectively. $[L]$ and $[T]$ are dimensions of length and time respectively. All the quantities are given in SI units.

The relation between $[\epsilon_0]$ and $[\mu_0]$ is

[\mu_0] = [\epsilon_0]\,[L]^2\,[T]^{-2}

[\mu_0] = [\epsilon_0]\,[L]^{-2}\,[T]^2

[\mu_0] = [\epsilon_0]^{-1}\,[L]^2\,[T]^{-2}

[\mu_0] = [\epsilon_0]^{-1}\,[L]^{-2}\,[T]^2

Answer and worked solution

Official answer: D

The speed of light is $c=\dfrac1{\sqrt{\mu_0\epsilon_0}}$ , so $[\mu_0][\epsilon_0]=[L]^{-2}[T]^2$ :
$[\mu_0]=[\epsilon_0]^{-1}[L]^{-2}[T]^2.$
(D)

Topics:Dimensional analysis Properties of EM waves

← Previous question Next question →

JEE Advanced 2018 · Paper 1, Physics question 16