When arsenic is added as an impurity to silicon, the resulting material is


Correct option is

n-type semiconductor

Arsenic is pentavalent. The addition each impurity atom makes an extra electron available for conduction. Thus the current carries are mainly electrons. Hence such semiconductors are called n-type semiconductors (n stands for negative current carriers).



In a transistor, a change of 8.0 mA in the emitter current produces a change of 7.8 mA in the collector current. What change in the base current is necessary to produce the same change in the collector current?


In a common emitter amplifier, the output resistance is  and the input resistance . In the peak value of the signal voltage is 10 mV and , then the peak value of the output voltage is 


The base current of a transistor is  and the collector current is 2 mA. What is the current gain for the common base configuration? 


In the depletion region of an unbiased pn junction diode, there are


An oscillator is nothing but an amplifier with


When Ge crystals are doped with phosphorus atom, then it becomes


The transfer ratio  of a transistor is 50. The input resistance of the when used in the common emitter configuration is . The peak value of the collector ac current for an ac input voltage for 0.01 V peak is


In a common base transistor circuit, the current gain is 0.98. On changing in the emitter current by 5.00 mA, the change in the collector current is


On increasing the reverse bias to a large value in a pn junction diode, the current  


What is the voltage gain in a common emitter amplifier, where the input resistance is  and load resistance ? Given .