Advertisements
Advertisements
प्रश्न
Why is the base of a transistor made thin and is lightly doped?
Advertisements
उत्तर
The base of a transistor is lightly doped than the emitter and narrowed so that almost all electrons injected from the emitter (in a n-p-n transistor) diffuse right across the base to the collector junction without recombining with holes. In other words, the base width is kept smaller than the recombination distance. In addition, to improve emitter efficiency and common-base current gain α, the emitter is much more heavily doped than the base.
APPEARS IN
संबंधित प्रश्न
In a common-base connection, a certain transistor has an emitter current of 10mA and a collector current of 9.8 mA. Calculate the value of the base current.
In a common base configuration, the transistor has an emitter current of 10 mA and a collector current of 9.8 mA. The value of base current is ______
For a transistor β =75 and IE = 7.5 mA. The value of α is ______
With the help of a neat diagram, explain the working of the npn transistor?
The output of the following circuit is 1 when the input ABC is
Sketch the static characteristics of a common emitter transistor and bring out the essential features of input and output characteristics.
Describe the function of a transistor as an amplifier with the neat circuit diagram. Sketch the input and output wave forms.
Assuming VCEsat = 0.2 V and β = 50, find the minimum base current (IB) required to drive the transistor given in the figure to saturation.
In the circuit shown in the figure, the BJT has a current gain (β) of 50. For an emitter-base voltage VEB = 600 mV, calculate the emitter-collector voltage VEC (in volts).
A common emitter amplifier is designed with n-p-n transistor (α = 0.99). The input impedance is 1 kΩ and the load is 10 kΩ. The voltage gain will be ______
A transistor having α = 0.8 is connected in common emitter configuration. When the base current changes by 6 mA, then the change in collector current is ______.
If `alpha`-current gain of a transistor is 0.98. What is the value of `beta`- current gain of the transistor?
In an npn transistor, the collector current is 24 mA. If 80% of electrons reach collector, its base current in mA is ______.
In case of npn transistors, the collector current is always less than the emitter current because ______.
For a common emitter configuration, if 'α' and 'β' have their usual meanings, the correct relationship between 'α' and 'β' is ______.
A pnp transistor is used in common-emitter mode. If a change of 40 µA in base current brings a change of 2 µA in collector current with 0.04 V in base-emitter voltage, then the input resistance is ____________.
The current gain `alpha` of a transistor is 0.95. The change in collector current corresponding to a change of 0.4 mA in the base current in a common emitter arrangement is ______.
In a transistor, doping level in base is increased slightly, the collector current and base current respectively ______.
A transistor is connected in C - E mode. If collector current is 72 × 10-5 A and α = 0.96, then base current will be ______.
For an ideal diode, the current in the following arrangement is ______.
A transistor having α = 0.8 is connected in a common emitter configuration. When the base current changes by 6 mA, the change in collector current is ______
A transistor is used as a common emitter amplifier with a load resistance 2 KΩ. The input resistance is 150 Ω. Base current is changed by 20 µA which results in a change in collector current by 1.5 mA. The voltage gain of the amplifier is ______.
In a p-n-p transistor circuit, the collector current is 10 mA. If 90% of the holes emitted from the emitter reach the collector, ______.
The reverse bias in a junction diode is changed from 8V to 13V, then the value of the current changes from 40μA to 60μA. The resistance of junction diode will be ______.
How is a transistor biased for operating it as amplifier?
Define α.
For a common emitter transistor configuration the ratio of `I_c/I_E` = 0.96, then the current gain in this configuration is ______.
