The ratio of contributions made by the electr | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) The intensity of an electromagnetic wave is given by $I = U_{av} c$.In terms of the electric field, the average energy density is $U_{av} = \frac{

Vedclass · Accepted Answer

$1 : 1$

Vedclass · Answer

(C) The intensity of an electromagnetic wave is given by $I = U_{av} c$.In terms of the electric field, the average energy density is $U_{av} = \frac{1}{2} \varepsilon_{0} E_{0}^{2}$.In terms of the magnetic field, the average energy density is $U_{av} = \frac{1}{2} \frac{B_{0}^{2}}{\mu_{0}}$.Since the relationship between the electric field amplitude $E_{0}$ and magnetic field amplitude $B_{0}$ is $E_{0} = c B_{0}$, we can substitute this into the electric field energy density expression:$U_{av} (	ext{electric}) = \frac{1}{2} \varepsilon_{0} (c B_{0})^{2} = \frac{1}{2} \varepsilon_{0} c^{2} B_{0}^{2}$.Using the relation $c^{2} = \frac{1}{\mu_{0} \varepsilon_{0}}$, we get:$U_{av} (	ext{electric}) = \frac{1}{2} \varepsilon_{0} \left( \frac{1}{\mu_{0} \varepsilon_{0}} ight) B_{0}^{2} = \frac{1}{2} \frac{B_{0}^{2}}{\mu_{0}} = U_{av} (	ext{magnetic})$.Thus, the contributions from both fields are equal, and the ratio is $1 : 1$.

The ratio of contributions made by the electric field and magnetic field components to the intensity of an electromagnetic wave is

Similar Questions

The $rms$ value of the electric field of the light coming from the sun is $720 \ N \ C^{-1}$. The average energy density of the electromagnetic wave is $...... \ J \ m^{-3}$.

$A$ microwave oven heats food containing water molecules very efficiently under which of the following conditions?

For a given electromagnetic wave,the magnitude of the electric field is $6.6 \,V \,m^{-1}$ at a point in space. The magnitude of the magnetic field at this point is . . . . . . $T$.

Give the relation between vacuum permittivity $(\epsilon_{0})$, vacuum permeability $(\mu_{0})$, and the speed of light $(c)$.

Electromagnetic waves with frequencies ranging from $2\,\text{MHz}$ to $30\,\text{MHz}$ are propagated by:

Vedclass Test Series

Exam Paper Generator

Online Exam Module