Advertisements
Advertisements
प्रश्न
An incomplete sentence about transistors is given below:
The emitter−..... junction is __ and the collector−..... junction is __. The appropriate words for the dotted empty positions are, respectively,
विकल्प
'collector' and 'base'
'base' and 'emitter'
'collector' and 'emitter'
'base' and 'base'.
उत्तर
'base' and 'base'
In transistors, the emitter−base junction is forward biassed and the collector−base junction is reverse biassed. This is done to make majority carriers cross the emitter−base junction; this helps the electric current to flow through the transistor.
APPEARS IN
संबंधित प्रश्न
Distinguish between a metal and an insulator on the basis of energy band diagrams ?
Write two characteristic features to distinguish between n-type and p-type semiconductors ?
Distinguish between a conductor, a semiconductor and an insulator on the basis of energy band diagrams.
There are energy bands in a solid. Do we have really continuous energy variation in a band ro do we have very closely spaced but still discrete energy levels?
In semiconductors, thermal collisions are responsible for taking a valence electron to the conduction band. Why does the number of conduction electrons not go on increasing with time as thermal collisions continuously take place?
When an electron goes from the valence band to the conduction band in silicon, its energy is increased by 1.1 eV. The average energy exchanged in a thermal collision is of the order of kT which is only 0.026 eV at room temperature. How is a thermal collision able to take some to the electrons from the valence band to the conduction band?
An electric field is applied to a semiconductor. Let the number of charge carries be nand the average drift speed by v. If the temperature is increased,
Calculate the number of states per cubic metre of sodium in 3s band. The density of sodium is 1013 kgm−3. How many of them are empty?
The band gap for silicon is 1.1 eV. (a) Find the ratio of the band gap to kT for silicon at room temperature 300 K. (b) At what temperature does this ratio become one tents of the value at 300 K? (Silicon will not retain its structure at these high temperatures.)
(Use Planck constant h = 4.14 × 10-15 eV-s, Boltzmann constant k = 8·62 × 10-5 eV/K.)
Find the maximum wavelength of electromagnetic radiation which can create a hole-electron pair in germanium. The band gap in germanium is 0.65 eV.
(Use Planck constant h = 4.14 × 10-15 eV-s, Boltzmann constant k = 8·62 × 10-5 eV/K.)
With reference to Semiconductor Physics,
Draw a labelled energy band diagram for a semiconductor.
What is forbidden band?
The energy of a hydrogen atom in the ground state is −13.6 eV. The energy of a He+ ion in the first excited state will be:
A hole in a. p – type semiconductor is
An n-type semiconductor is
In a common base configuration Ie = 1 mA α = 0.95 the value of base current is
With reference to semiconductor physics, answer the following question.
In which material “Forbidden band” is absent?
