Consider a situation in which reverse biased current of a particu… - Vidyadip

Question

Consider a situation in which reverse biased current of a particular $P-N$ junction increases when it is exposed to a light of wavelength $\le 621\, {nm}$. During this process, enhancement in carrier concentration takes place due to generation of hole-electron pairs. The value of band gap is nearly. (In ${eV}$)

✓

Answer

b
Band gap $=\frac{h c}{\lambda_{0}}$

Where $\lambda_{0}=$ threshold wavelength

Band gap $=\frac{1242\, {ev}-\,{nm}}{621\, {nm}}=2\, {ev}$

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

A sphere encloses an electric dipole with charge $\pm 3 \times 10^{-6} \;\mathrm{C} .$ What is the total electric flux across the sphere?......${Nm}^{2} / {C}$

Two tuning forks $A\,\, \& \,\,B$ produce notes of frequencies $256 Hz \,\,\& \,\,262 Hz$ respectively. An unknown note sounded at the same time as $A$ produces beats . When the same note is sounded with $B$, beat frequency is twice as large . The unknown frequency could be ... $Hz$

A cyclic process is shown in figure. Work done during isobaric expansion is ...... $J$

The radiant energy from the sun incident normally at the surface of earth is $20\, \frac{{k\;cal}}{{{m^2}\;min}}$. What would have been the radiant energy incident normally on the earth, if the sun had a temperature twice of the present one ....... $kcal/m ^2 \,min$

Two conductors are made of the same material and have the same length. Conductor $A$ is a solid wire of diameter $1.0\, mm$. Conductor $B$ is a hollow tube of outside diameter $2.0\, mm$ and inside diameter $1.0\, mm$. The resistance ratio $R_A/R_B$ will be

A block of mass $5 kg$ is at rest on a rough inclined surface. If angle of inclination of plane is $60^{\circ}$, then force applied by it on block is .......... $N$

A block of mass $m =1\, kg$ slides with velocity $v=6\, m / s$ on a frictionless horizontal surface and collides with a uniform vertical rod and sticks to it as shown. The rod is pivoted about $O$ and swings as a result of the collision making angle $\theta$ before momentarily coming to rest. If the rod has mass $M =2 \,kg $ and length $l=1\, m$ the value of $\theta$ is approximately

(Take $\left.g=10 \,m / s ^{2}\right)$

Two vibrating tuning forks produce progressive waves given by ${y_1} = 4\,\sin \,\left( {500\pi t} \right)$ and ${y_2} = 2\,\sin \,\left( {506\pi t} \right)$. These tuning forks are held near the ear of a person. The person will hear $\alpha \, beats/s$ with intensity ratio between maxima and minima equal to $\beta $. Find the value of $\beta - \alpha $

The coefficient of performance of a refrigerator is $5.$ If the temperature inside freezer is $-20^o C,$ the temperature of the surroundings to which it rejects heat is ........ $^oC$

In the propagation of electromagnetic waves the angle between the direction of propagation and plane of polarisation is......$^o$