The Electrical Conductivity Of  a Semiconductor Inceases When Electromagnetic Radiation Of Wavelength Shorter Than 2480 Nm Is Incident On It. Find The Band Gap For The Semiconductor. Given : .  

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The electrical conductivity of  a semiconductor inceases when electromagnetic radiation of wavelength shorter than 2480 nm is incident on it. Find the band gap for the semiconductor. Given :



Correct option is

0.5 eV

The band gap is the maximum energy required to push an electron from the valence band into the semiconductor, that is,





            = 0.5 eV.




Pure Si at 300 K has equal electron (ne) and hole (nh) concentrations of . Doping by indium increases nh to . Calculate ne in the dopped Si.


A semiconductor has equal electron and hole concentrations of . On doping with a certain impurity, the hole concentration increases to . Calculate the new electron concentration of the semiconductor.   


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A semiconductor is known to have an electron concentration of  and a hole concentration of . Is the semiconductor n-type or p-type? What is the resistivity of the sample if the electron mobility is 23,000 cm2V–1s–1 and hole mobility is 100 cm2V–1s–1.


At absolute zero of temperature, the electrical conductivity of a pure semiconductor is


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In a transistor circuit, the collector current is 50 mA and the base current is 1 mA. The current gain  is