The electromagnetic waves travel with a velocity
The electromagnetic waves travel with a velocity
- A
Equal to velocity of sound
- B
Equal to velocity of light
- C
Less than velocity of light
- D
None of these
Similar Questions
The electric field associated with an em wave in vacuum is given by $\vec{E}=\hat{i} 40 \cos \left(k z-6 \times 10^{8} t\right)$ where $E, x$ and $t$ are in $volt/m,$ meter and seconds respectively. The value of wave vector $k$ is....$ m^{-1}$
The electric field associated with an em wave in vacuum is given by $\vec{E}=\hat{i} 40 \cos \left(k z-6 \times 10^{8} t\right)$ where $E, x$ and $t$ are in $volt/m,$ meter and seconds respectively. The value of wave vector $k$ is....$ m^{-1}$
- [AIPMT 2012]
A point source of $e. m.$ radiation has an average power output of $800\,W$ . The maximum value of electric field at a distance $4.0\,m$ from the source is...$V/m$
A point source of $e. m.$ radiation has an average power output of $800\,W$ . The maximum value of electric field at a distance $4.0\,m$ from the source is...$V/m$
Show that the radiation pressure exerted by an $EM$ wave of intensity $I$ on a surface kept in vacuum is $\frac{I}{c}$.
Show that the radiation pressure exerted by an $EM$ wave of intensity $I$ on a surface kept in vacuum is $\frac{I}{c}$.
If a source of electromagnetic radiation having power $15 kW$ produces $10^{16}$ photons per second, the radiation belongs to a part of spectrum is.(Take Planck constant $h =6 \times 10^{-34}\,Js$ )
If a source of electromagnetic radiation having power $15 kW$ produces $10^{16}$ photons per second, the radiation belongs to a part of spectrum is.(Take Planck constant $h =6 \times 10^{-34}\,Js$ )
- [JEE MAIN 2023]
A $27\, mW$ lager beam has a cross -sectional area of $10\, mm^2$. The magnitude of the maximum electric field in this electromagnetic wave is given by:........$kV/m$ [Given permittivity of space ${ \in _0} = 9 \times {10^{ - 12}}\, SI\, units$, speed of light $c = 3 \times 10^8\, m/s$]
A $27\, mW$ lager beam has a cross -sectional area of $10\, mm^2$. The magnitude of the maximum electric field in this electromagnetic wave is given by:........$kV/m$ [Given permittivity of space ${ \in _0} = 9 \times {10^{ - 12}}\, SI\, units$, speed of light $c = 3 \times 10^8\, m/s$]
- [JEE MAIN 2019]