MCQ
An electromagnetic wave going through vacuum is described by $\text{E}=\text{E}_0\sin(\text{kx}-\omega\text{t}),\text{ B}=\text{B}_0\sin(\text{kx}-\omega\text{t})$ Then:
  • $\text{E}_0\text{k}=\text{B}_0\omega$
  • B
    $\text{E}_0\text{B}_0=\omega\text{k}$
  • C
    $\text{E}_0\omega=\text{B}_0\text{k}$
  • D
    None of these.

Answer

Correct option: A.
$\text{E}_0\text{k}=\text{B}_0\omega$

The relation between $E _0$ and $B _0$ id given by $\frac{\text{E}_0}{\text{B}_0}=\text{c}\ ....(\text{i})$
Here, $c =$ Speed of the electromagnetic wave,
The relation between $\omega ($the angular frequency$)$ and $k\ ($wave number$),$
$\frac{\omega}{\text{k}}=\text{c}\ ...(\text{ii})$
Therefore, from $(i)$ and $(ii),$ we get
$\frac{\text{E}_0}{\text{B}_0}=\frac{\omega}{\text{k}}=\text{c}$
$\text{E}_0\text{k}=\text{B}_0\omega$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Monochromatic green light of wavelength $5 \times 10^{-7} m$ illuminates a pair of slits 1 mm apart. The separation of bright lines on the interference pattern formed on a screen 2 m away is
A conductor ABOCD moves along its bisector with a velocity of 1 m/s through a perpendicular magnetic field of 1 wb/m$^2$, as shown in fig. If all the four sides are of 1m length each, then the induced emf between points A and D is
Two small metal balls of different masses $m_1$ and $m_2$ are connected by strings of equal length to a fixed point. When the balls are given equal charges, the angles that the two strings make with the vertical are $30^{\circ}$ and $60^{\circ}$, respectively. The ratio $m_1 / m_2$ is close to
Spectrum of sunlight is an example for:
A parallel plate capacitor $\mathrm{C}$ with plates of unit area and separation $\mathrm{d}$ is filled with a liquid of dielectric constant $\mathrm{K}=2$. The level of liquid is $\frac{\mathrm{d}}{3}$ initially. Suppose the liquid level decreases at a constant speed $V,$ the time constant as a function of time $t$ is Figure: $Image$
To convert a $800\, mV$ range milli voltmeter of resistance $40 \,\Omega$ into a galvanometer of $100\, mA$ range, the resistance to be connected as shunt is .............. $\Omega $
In the circuit shown, the current through the $4\,\Omega $ resistor is $1\, amp$ when the points $P$ and $M$ are connected to a d.c. voltage source. The potential difference between the points $M$ and $N$ is ............... $volt$
The triode constant is out of the following
Which of the following statement is false:
The half life period of a radioactive substance is 5 min. The amount of substance decayed in 20 min will be