Using monochromatic light of wavelength , an experimentalist sets… - Vidyadip

MCQ

Using monochromatic light of wavelength $\lambda $, an experimentalist sets up the Young 's double slit experiment in three ways as shown. If she observes that $y = \beta '$, the wavelength of light used is.....$nm$

A
$520$
✓
$540$
C
$560$
D
$580$

✓

Answer

Correct option: B.

$540$

b
Given $t=1.8 \times 10^{-6} \mathrm{m}$

$\mu=1.6$

$\mathrm{n}=2(\text { from figure })$

Applying formula $(\mu-1) \mathrm{t}=\mathrm{n} \lambda$

$(1.6-1) \times 1.8 \times 10^{-6}=2 \lambda$

or, ${\lambda = \frac{{1.8 \times {{10}^{ - 6}} \times 0.6}}{2}}$

$=\,540 \,\mathrm{nm}$

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

Explore more

More "M.C.Q (1 Marks)" from 10. Wave optics→10. Wave optics — all question types→Physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

One Volt is equal to:

A circuit has a section $AB$ as shown in the figure. If the potential difference between points $A$ and $B$ is $V\, volt$, then potential difference across $C_1$ is

The $SI$ unit of inductance, the henry, can be written as

A semiconductor device is connected in a series circuit with a battery and a resistance. A current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops to almost zero. The device may be a/ an?

A beam of light propagating in medium $A$ with index of refraction $n(A)$ passes across an interface into medium $B$ with index of refraction $n(B)$. The angle of incidence is greater than the angle of refraction; $v(A)$ and $v(B)$ denotes the speed of light in $A$ and $B.$ Then which of the following is true

Three infinitely long charged thin sheets are placed as shown in figure. The magnitude of electric field at the point $P$ is $\frac{x \sigma}{\in_0}$. The value of $x$ is_____. (all quantities are measured in $SI$ units).

A current $I$ enters a circular coil of radius $R$, branches into two parts and then recombines as shown in the circuit diagram. The resultant magnetic field at the centre of the coil is

Consider a metallic cube of edge length $L$. Its resistance, $R$, measured across its opposite faces is $R =\frac{ m _{ e } v }{ ne ^2 L ^2}$, where $n$ is the number density and $v$ is the drift speed of electrons in the cube, and $e$ and $m _{ e }$ are the charge and mass of an electron respectively. Assuming the de-Broglie wavelength of the electron to be $L$, the maximum resistance of the sample is closest to ............. $\,\Omega$ $\left(e=1.60 \times 10^{-19} \,C ; m _{ e }=9.11 \times 10^{-31} \,kg\right.$; Planck's constant, $h=6.63 \times 10^{-34} \,Js$ )

The resistance of a galvanometer is $90\, ohms$. If only $10$ percent of the main current may flow through the galvanometer, in which way and of what value, a resistor is to be used

$NPN$ transistor are preferred to $PNP$ transistor because they have