White light is passed through a double slit and interference is o… - Vidyadip

MCQ

White light is passed through a double slit and interference is observed on a screen $1.5 \,{m}$ away. The separation between the slits is $0.3 \,{mm}$. The first violet and red fringes are formed $2.0 \,{mm}$ and $3.5\, {mm}$ away from the central white fringes. The difference in wavelengths of red and voilet light is $.... \,{nm} .$

A
$150$
B
$1300$
✓
$300$
D
$600$

✓

Answer

Correct option: C.

$300$

c
Position of bright fringe ${y}={n} \frac{{D} \lambda}{{d}}$

${y}_{1} \text { of red }=\frac{{D} \lambda_{{r}}}{{d}}=3.5\, {mm}$

$\lambda_{{T}}=3.5 \times 10^{-3} \frac{{d}}{{D}}$

Similarly $\lambda_{{v}}=2 \times 10^{-3} \frac{{d}}{{D}}$

$\lambda_{{r}}-\lambda_{{v}}=\left(1.5 \times 10^{-3}\right)\left(\frac{0.3 \times 10^{-3}}{1.5}\right)$

$=3 \times 10^{-1}=300\, {nm}$

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

JEE STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Conductivity of a photodiode starts changing only if the wavelength of incident light is less than $660 \ nm .$ The band gap of photodiode is found to be $\left(\frac{ X }{8}\right) eV$. The value of $X$ is $: ($Given, $h =6.6 \times 10^{-34} Js , e =1.6 \times 10^{-19} C )$

A body is revolving with a uniform speed $v$ in a circle of radius $r$. The tangential acceleration is

A particle is moving with a constant speed along a straight line path. A force is not required to

If $L$ is the angular momentum of a satellite revolving around earth is a circular orbit of radius $r$ with speed $v$, then .........

On applying a stress of $20 \times {10^8}N/{m^2}$ the length of a perfectly elastic wire is doubled. Its Young’s modulus will be

Two point sources $X$ and $Y$ emit waves of same frequency and speed but $Y$ lags in phase behind $X$ by $2 \pi l$ radian. If there is a maximum in direction $D$ the distance $XO$ using n as an integer is given by

A force applied by an engine of a train of mass $2.05 \times {10^6}\;kg$ changes its velocity from $5\;m/s$ to $25\;m/s$ in $5$ minutes. The power of the engine is ........... $MW$

A cell of internal resistance $3\, ohm$ and $emf$ $10\, volt$ is connected to a uniform wire of length $500 \,cm$ and resistance $3\, ohm$. The potential gradient in the wire is .............. $mV/cm$

A radioactive element $_{90}{X^{238}}$ decay into $_{83}{Y^{222}}$. The number of $\beta - $ particles emitted are

A wave disturbance in a medium is described by $y(x,\,t) = 0.02\cos \,\left( {50\,\pi t + \frac{\pi }{2}} \right)\cos (10\pi x)$, where $ x$ and $y$ are in metres and $t$ in seconds