27 questions · self-marked practice — reveal the answer and mark yourself.
Explanation:
The wave is travelling along the X-axis. So, it'll have planar wavefront perpendicular to the X-axis.
Explanation:
Frequency of a light wave doesnt change on changing the medium of propagation of light.
Explanation:
Light shows photoelectric effect and Compton effect, which depicts its particle nature. It also shows interference and diffraction, which depicts the wave nature of light.
Explanation:
Ratio of maximum intensity and minimum intensity is given by
$\frac{\text{I}_\text{max}}{\text{I}_\text{min}}=\frac{(\sqrt{\text{I}_1}+\sqrt{\text{I}_2})^2}{(\sqrt{\text{I}_1}-\sqrt{\text{I}_2})^2}=\frac{25}{1}$
$\Rightarrow\sqrt{\text{I}_1}=3 \ \text{and}\ \sqrt{\text{I}_2}=2$
$\Rightarrow\text{I}_1=9\ \text{and}\ \text{I}_2=4$
Then,
$\frac{\text{I}_1}{\text{I}_2}=\frac{9}{4}$
The central fringe will be white.
There will not be a completely dark fringe.
The fringe next to the central will be violet.
Explanation:
The superposition of all the colours at the central maxima gives the central band a white colour. As we go from the centre to corner, the fringe colour goes from violet to red. There will not be a completely dark fringe, as complete destructive interference does not take place.
Explanation:
Light consists of mutually perpendicular electric and magnetic fields. So, the equation of a light wave is represented by its field vector.
Explanation:
Reflection, interference and diffraction are the phenomena shown by both transverse waves and longitudinal waves. Polarization is the phenomenon shown only by transverse waves.
$\text{v}_\text{A}>\text{v}_\text{B}>\text{v}_\text{C}$
$\text{v}_\text{B}=\frac{1}{2}(\text{v}_\text{A}+\text{v}_\text{C})$
Explanation:
Since the speed of light is a universal constant,
$\text{v}_\text{A}=\text{v}_\text{B}=\text{v}_\text{C}=3\times 10^8\text{m/s}$
$\text{v}_\text{B}=\frac{1}{2}(\text{u}_\text{A}+\text{u}_\text{C})$ This expression also implies that vA = vB = vC
Explanation:
Interference effect is produced by a thin film (coating of a thin layer of a translucent material on a medium of different refractive index which allows light to pass through it). ln the present case, oil floating on water forms a thin film on the surface of water, leading to the display of beautiful colours in daylight because of the interference of sunlight.
Explanation:
On the introduction of a transparent sheet in front of one of the slits, the fringe pattern will shift slightly but the width will remain the same.
Explanation:
For light waves emitted by two sources of light to remain coherent, the initial phase difference between waves should remain constant in time. If the phase difference changes continuously or randomly with time, then the sources are incoherent.
Explanation:
Light is an electromagnetic wave that propagates through its electric and magnetic field vectors, which are mutually perpendicular to each other, as well as to the direction of propagation of light. The average value of both the fields is zero.
Explanation:
Light is an electromagnetic wave that can travel through vacuum or any optical medium.
Explanation:
Huygen's wave theory explains the origin of points for the new wavefront proceeding successively. It also explains the variation in speed of light on moving from one medium to another, i.e. it proves Snell's Law.
Explanation:
Snell's Law, which states that the speed of light reduces on moving from a rarer to a denser medium, can be concluded from Huygens' wave theory and interference of light waves is based on the wave properties of light.
Explanation:
The speed of light in any medium depends on the refractive index of that medium, which is an intensive property. Hence, speed of light is not affected by the elasticity and inertia of the medium.
Explanation:
Among the given sources, laser is the best coherent source providing monochromatic light with constant phase difference.
Explanation:
Wave travelling from a distant source always has plane wavefront.
$\text{y}=\text{a}_1\sin\omega\text{t}$
$\text{y}=\text{a}_2\sin(\omega\text{t}+\in)$
$\text{y}=\text{a}_1\sin2\omega\text{t}$
$\text{y}=\text{a}_2\sin2(\omega\text{t}+\in)$
Explanation:
The waves are travelling with the same frequencies and varying by constant phase difference.
Explanation:
Intensity of a point source obeys the inverse square law.
Intensity of light at distance r from the point source is given by
$\text{I}=\frac{\text{S}}{(4\pi\text{r}^2)}$
Where S is the source strength.
$\text{I}_0$
$\frac{\text{I}_0}{4}$
$\frac{\text{I}_0}{2}$
$4\text{I}_0$
Explanation:
Total intensity coming from the source is I0 which is present at the central maxima. In case of two slits, the intensity is getting distributed between the two slits and for a single slit, the amplitude of light coming from the slit is reduced to half which leads to $\frac{1}{4}\text{th}$ of intensity.
$0^\circ$
$45^\circ$
$90^\circ$
$\cos^{-1}\Big(\frac{1}{\sqrt{3}}\Big)$
Explanation:
On writing the given equation in the plane equation form lx + my + nz = p,
Where l2 + m2 + n2 and p > 0, we get:
$\frac{1}{\sqrt{3}}\text{x}+\frac{1}{\sqrt{3}}\text{y}+\frac{1}{\sqrt{3}}\text{z}=\frac{\text{c}}{\sqrt{3}}$
If $\theta$ is the angle between the normal and +x axis, then
$\cos\theta=\frac{1}{\sqrt{3}}$
$\Rightarrow\theta=\cos^{-1}\Big(\frac{1}{\sqrt{3}}\Big) $
$\lambda_\text{a}>\lambda_\text{f}$
$\lambda_\text{a}=\lambda_\text{f}$
$\lambda_\text{a}<\lambda_\text{f}$
Explanation:
An electromagnetic wave bends round the corners of an obstacle if the size of the obstacle is comparable to the wavelength of the wave. An AM wave has less frequency than an FM wave, So, an AM wave has a higher wavelength than an FM wave and it bends round the comers of a 1m × 1m board.
$\text{v}_\text{A}>\text{v}_\text{B}>\text{v}_\text{C}.$
$\text{v}_\text{A}<\text{v}_\text{B}<\text{v}_\text{C}$
$\text{v}_\text{A}=\text{v}_\text{B}=\text{v}_\text{C}$
$\text{v}_\text{B}=\frac{1}{2}(\text{v}_\text{A}+\text{v}_\text{C})$
$\text{v}_\text{A}=\text{v}_\text{B}=\text{v}_\text{C}$
$\text{v}_\text{B}=\frac{1}{2}(\text{v}_\text{A}+\text{v}_\text{C})$
Explanation:
Since the speed of light is a universal constant, $\text{v}_\text{A}=\text{v}_\text{B}=\text{v}_\text{C}=3\times10^8\text{m/s.}$
$\text{v}_\text{B}=\frac{1}{2}(\text{u}_\text{A}+\text{u}_\text{C})$ This expression also implies that vA = vB = vC.
Explanation:
As fringe width is proportional to the wavelength and wavelength of light is inversely proportional to the refractive index of the medium,
Here,
$\lambda_\text{M}=\frac{\lambda}{\eta}$
$\lambda_\text{M}$ = wavelength in medium
$\lambda$ = wavelength in vacuum
$\eta$ = refractive index of medium
Hence, fringe width decreases when Young's double slit experiment is performed under water.
Explanation:
Fringe width, $\beta=\frac{\lambda\text{D}}{\text{d}}$
Wavelength of red light is greater than wavelength of violet light; so, the fringe width will reduce.
Explanation:
Frequency of a light wave, as it travels from one medium to another, always remains unchanged, while wavelength decreases.
Decrease in the wavelength of light entering a medium of refractive index $\mu$, is given by,
$\lambda_\text{M}=\frac{\lambda}{\mu},$
Where $\lambda_\text{M}$ = wavelength in medium
$\lambda$ = wavelength in vacuum
$\mu$ = refractive index