Carbon, silicon and germanium have four valence electrons each. These are characterised by valence and conduction bands separated by energy band gap respectively equal to (Eg)C, - Physics

Advertisements
Advertisements
MCQ

Carbon, silicon and germanium have four valence electrons each. These are characterised by valence and conduction bands separated by energy band gap respectively equal to (Eg)C, (Eg)Si and (Eg)Ge. Which of the following statements is true?

Options

  • (Eg)Si < (Eg)Ge < (Eg)C

  • (Eg)C < (Eg)Ge > (Eg)Si

  • (Eg)C > (Eg)Si > (Eg)Ge

  • (Eg)C = (Eg)Si = (Eg)Ge

Advertisements

Solution

(Eg)C > (Eg)Si > (Eg)Ge

Explanation:

Of the three given elements, the energy band gap of carbon is the maximum and that of germanium is the least.

The energy band gap of these elements are related as: (Eg)C > (Eg)Si > (Eg)Ge

  Is there an error in this question or solution?
Chapter 14: Semiconductor Electronics: Materials, Devices and Simple Circuits - Exercise [Page 497]

APPEARS IN

NCERT Physics Class 12
Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits
Exercise | Q 14.3 | Page 497
NCERT Physics Class 12
Chapter 14 Semiconductor Electronics: Materials, Devices and Simple Circuits
Exercise | Q 3 | Page 509

RELATED QUESTIONS

With the help of a neat circuit diagram, explain the working of a photodiode. 


Colour of light emitted by LED depends upon__________________ .

  1. its forward bias
  2. its reverse bias
  3. the band gap of the material of semiconductor
  4. its size

If a small voltage is applied to a p-n junction diode, how will the barrier potential be affected when it is (i) forward biased


If a small voltage is applied to a p-n junction diode, how will the barrier potential be affected when it is(ii) reveres biased?


The width of depletion region of p-n junction diode is _______.

(A) 0.5 nm to 1 nm

(B) 5 nm to 10 nm

(C) 50 nm to 500 nm

(D) 500 nm to 1000 nm

 


State its any ‘two’ uses of photodiode.


Sunil and his parents were travelling to their village in their car. On the way his mother noticed some grey coloured panels installed on the roof of a low building. She enquired from Sunil what those panels were and Sunil told his mother that those were solar panels.
(a) What were the values displayed by Sunil and his mother? State one value for each.
(b) In what way would the use of solar panels prove to be very useful?
(c) Name the semiconductor device used in solar panels. Briefly explain with the help of a diagram, how this device works


Show the output waveforms (Y) for the following inputs A and B of (i) OR gate (ii) NAND gate ?


Describe briefly, with the help of a diagram, the role of the two important processes involved in the formation of a p-n junction ?


Explain the formation of depletion layer and potential barrier in a p−n junction.


An ideal diode should pass a current freely in one direction and should stop it completely in the opposite direction. Which is closer to ideal-vacuum diode or a p-njunction diode?


The plate resistance of a triode is 8 kΩ and the transconductance is 2.5 millimho. (a) If the plate voltage is increased by 48 V and the grid voltage is kept constant, what will be the increase in the plate current? (b) With plate voltage kept constant at this increased value, by how much should the grid voltage be decreased in order to bring the plate current back to its initial value?


Draw the V-I characteristics of an LED. State two advantages of LED lamps over convertional  incandescent lamps. 


What is a solar cell?


Answer the following question.
Draw solar cell V-I characteristics.


With reference to Semiconductor Physics,

Name the process that causes depletion region in a p-n junction.


Explain photodiode.


What is the magnitude of the potential barrier across a Ge p-n junction?


Pressure P varies as P = `alpha/beta "exp" (- (alpha x)/"k"_"BT")`, where x denotes the distance, kB is the Boltzmann's constant, T is the absolute temperature and α and β are constant. The dimension of β is ______.


A p-n photodiode is fabricated from a semiconductor with a band gap of 2.5 eV. lt can detect a signal of wavelength ______.


For LED's to emit light in visible region of electromagnetic light, it should have energy band gap in the range of:


Which one of the following is not the advantage of LED?


Consider the following statements (A) and (B) and identify the correct answer.

  1. A Zener diode is connected in reverse bias when used as a voltage regulator.
  2. The potential barrier of the p-n junction lies between 0.1 V to 0.3 V.

In Figure, assuming the diodes to be ideal ______.


Draw the circuit diagram of an illuminated photodiode and its I-V characteristics.


How can a photodiode be used to measure light intensity?


The value of power dissipated across the Zener diode (Vz = 15 V) connected in the circuit as shown in the figure is x × 10–1 watt. The value of x, to the nearest integer, is ______.


Share
Notifications



      Forgot password?
Use app×