Question

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

Solution

Correct option is

An n-type semiconductor

Phosphorus is a pentavalent atom. When a pentavalent impurity is added to a semiconductor, we obtain an n-type semiconductor.   

SIMILAR QUESTIONS

Q1

In pure silicon at 300 K the electron and hole concentration is each equal to . When doped with indium, the hole concentration increases to . What is the electron concentration in doped silicon?

Q2

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

Q3

In a transistor circuit, the collector current is 9.8 mA and the base current is 10 mA. The current gain  is 

Q4

In a transistor amplifier, the two ac current gains  as defined as . The relation between  is

Q5

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?

Q6

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 

Q7

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

Q8

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

Q9

An oscillator is nothing but an amplifier with

Q10

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