Speed of light and optical density - class-XI
Description: speed of light and optical density | |
Number of Questions: 33 | |
Created by: Shaka Gupte | |
Tags: ray optics and optical instruments light energy physics refraction of light option a: relativity optics |
Choose the correct answer from the alternatives given.
An electromagnetic wave of frequency $\nu= 3\ MHz$ passes from vacuum into a dielectric medium with permittivity $\varepsilon= 4$. Then
An electromagnetic wave is propagating along x-axis. At x = 1 m and t = 10 s, its electric vector |$\overset{-}{E}| = 6 V/m$ then the magnitude of its magnetic vector is:
The electric field associated with an electromagnetic wave in vacuum is given by $|\overrightarrow { E } |= 40\ cos (kz -6\times{10}^{8}t )$, where $E$, $z$ and $t$ are in volt per meter, meter and second respectively. The value of wave vector $k$ is:
If the relative permeability of a medium is $ \mu _r$ and its dielectric constant is $\varepsilon _r$ then the velocity of light in that medium will be
The speed of electromagnetic wave in vacuum depends upon the source of radiation. It
The electromagnetic waves travel with a velocity
The speed of electromagnetic wave is same for
The formula for the velocity of electromagnetic waves in vacuum is given by
The amplitudes $E _{0}$ and $B _{0}$ of electric and the magnetic component of an electromagnetic wave respectively are related to the velocity $c$ in vacuum as
An electromagnetic wave passing through the space is given by equations $E=E _o\sin(wt-kx), B=B _0\sin(wt-kx)$ which of the following is true?
If a source of power $4kW$ produces $10^{20}$ photons/second, the radiation belongs to a part of the spectrum called:
For a medium with permitivity $\epsilon$ and permeability $\mu$, the velocity of light is given by:
If $C=$ the velocity of light, which of the following is correct?
The wave function (in S.I. units) for an electromagnetic wave is given as-
$\psi (x, t) = 10^{3} \sin \pi (3\times 10^{6} x - 9\times 10^{14}t)$ The speed of the wave is:
The electric field part of an electromagnetic wave in a medium is represented by $ { E } _{ x }=0 $ ;
$ { E } _{ y }=2.5\frac { N }{ C } cos[(2\pi \times { 10 }^{ 6 }\frac { rad }{ s } )t-(\pi \times { 10 }^{ -2 }\frac { rad }{ m } )x] $ ;
$ { E } _{ z }=0 $.The wave is:
The velocity of electromagnetic waves in free space is $3 \times 10^6 m/sec$. The frequency of a radio wave of wavelength $150 m$, is:-
If $v _s$ , $v _x$ and $v _m$ are the velocities of soft gamma rays, X-rays and Microwaves respectively in vacuum, then
If velocity of an electromagnetic wave in a medium is $3\times 10^8m/s$ then find refractive index of medium.
Three observers $A,B$ and $C$ measure the speed of light coming from a source as $v _A,v _B$ and $v _C$. Observer $A$ moves towards the source, $C$ moves away from source and $B$ stays stationary. The surrounding medium is water. If A and C are moving at the same speed, then
Three observers $A,B$ and $C$ measure the speed of light coming from a source to be $v _A,v _B$ and $v _C$. The observer $A$ moves towards the source and $C$ moves away from the source at the same speed. The observer $B$ stays stationary. The surrounding space is vacuum everywhere.
Which of the following properties of light conclusively support wave theory of light?
An electromagnetic wave of frequency $v=3.0:MHz$ passes from vacuum into a dielectric medium with permittivity $\epsilon=4.0$. Then
The electromagnetic waves
The apparent wavelength of light from a star moving away from the earth is 0.02% more than actual wavelength. What is the velocity of the star.
All colours travel with the same speed in :
An electromagnetic wave of frequency $\mathrm{v}=3.0$ MHz passes from vacuum into a dielectric medium with permittivity $\epsilon =4.0$. Then :
The velocity of electromagnetic radiation in a medium of permittivity ${\varepsilon} _{0}$ and permeability ${\mu} _{0}$ is given by :
A certain color of light towards the purple end of the visible spectrum has a wavelength of $420\ nm$ in a vacuum.
What is the frequency of this light?
The speed of light in a vacuum is $3.00\times 10^8 m/s$
Blue light of wavelength $480\ nanometers$, is most strongly reflected off a thin film of oil on a glass slide, when viewed near normal incidence. Assuming that the index of refraction of the oil is $1.2$ and that of the glass is $1.6$, what is the minimum thickness of the oil film (other than zero)?
When light is refracted into a denser medium,
Mark the correct statements (s) for a very thin soap film (RI = 1.33) whose thickness is much less then wavelength of visible light.
When a ray of light enters glass from water, it bends :
A convex lens forms a real image with magnification $m _1$ on a screen. Now, the screen is moved by a distance x and the object is also moved so as to obtain a real image with magnification $m _2 (> m _1) $ on the screen. Then, the focal length of the lens is