In an electromagnetic wave in free space the root mean square value of the electric field is $E_{rms}=6$ V/m. The peak value of the magnetic field is:

1. 1.41$\times {10}^{-8}T$

2. $2.83\times {10}^{-8}T$

3. $0.70\times {10}^{-8}T$

4. $4.23\times {10}^{-8} T$

The energy of the EM wave is of the order of 15 KeV. To which part of the spectrum does it belong?

1. X-rays

2. Infrared rays

3. Ultraviolet rays

4. $\gamma$-rays

The electric field associated with an electromagnetic wave in vacuum is given by E= 40cos$\left(kz-6\times {10}^{8}t\right),$where E, z, and t are in volt/m, meter, and second respectively. The value of wave vector k is:

1. $2 m^{-1}$                               2. $0.5 m^{-1}$

3. $6 m^{-1}$                               4. 3 $m^{-1}$             

The decreasing order of the wavelength of infrared, microwave, ultraviolet and gamma rays is:

The electric field of an electromagnetic wave in free space is given by $\overrightarrow{\mathbf{E}}=10 \cos ({10}^{7}t+kx)\hat{\mathbf{j}} \mathrm{V}/\mathrm{m},$ where t and x are in seconds and meters respectively. It can be inferred that

(1) The wavelength $\mathrm{\lambda }$ is 188.4 m.

(2) The wave number k is 0.33 rad/m.

(3) The wave amplitude is 10 V/m.

(4) The wave is propagating along +x direction

Which one of the following pairs of statements is correct?

1.  (3) and (4)                                    2.   (1) and (2)

3.   (2) and (3)                                   4.   (1) and (3)  

The electric field part of an electromagnetic wave in a medium is represented by :

${\mathrm{E}}_{\mathrm{x}}=0;$
${\mathrm{E}}_{\mathrm{y}}=(2.\mathrm{5 }\frac{\mathrm{N}}{\mathrm{C}}\mathrm{)cos}\left[\left(2\mathrm{\pi }\times {10}^6\frac{\mathrm{rad}}{s}\right)\mathrm{t}\right]$ $-\left(\mathrm{\pi }\times {10}^{-2}\frac{\mathrm{rad}}{m}\right)\mathrm{x}$
${\mathrm{E}}_{\mathrm{z}}=0.$
$\mathrm{The}$ $\mathrm{wave}$ $\mathrm{is:}$

Which of the following rays are not electromagnetic waves ?

(a) $\mathrm{\gamma }$-rays                  (b) $\mathrm{\beta }$-rays
(c) Heat rays              (d) X-rays

Statement-I: Gamma rays are more energetic than X-rays.

Statement-II: Gamma rays are of nuclear origin but X-rays are produced due to sudden deceleration of high energy electrons while falling on a metal of high atomic number.

(1) If both statement-I and Statement-II are true, and Statement-II is the correct explanation of Statement-I.

(2) If both Statement-I and Statement-II are true but Statement-II is not the correct explanation of Statement-I.

(3) If Statement-I is true but Statement-II is false.

(4) If Statement-I is false but Statement-II is true.

The S.I unit of displacement current is

(1) Henry

(2) Coulomb

(3) Ampere

(4) Farad

An electromagnetic wave going through Vaccum is described by

$E=E_0\sin (kx-\omega t)$
$B=B_0\sin (kx-\omega t)$

(1) $E_0{B}_0=\omega k$

(2) $E_0\omega =B_{0}k$

(3) $E_{0}k=B_0\omega$

(4) none of these