Table of Contents
In which mode transistor works as an amplifier?
The transistor can work in three different regions like active region, cutoff region & saturation region. Transistors are turned off while working in the cut-off region and turned on while working in the saturation region. Transistors work as an amplifier while they work in the active region.
How can a transistor be used as an amplifier or a switch?
The transistor can be used as a switch or as an amplifier by forward/reverse biasing the emitter to base and base to collector junctions. Based on biasing, the transistor can be operated in cut off, active and saturation region of the transfer characteristics of the transistor.
When an NPN transistor is used as an amplifier?
For a npn transistor to be used as an amplifier, forward bias has to be applied on the transistor. Thus, when an npn transistor is used as an amplifier, holes move from base to emitter. So, the correct answer is option D i.e. holes move from base to emitter.
How do you wire a transistor as a switch?
To connect the transistor as a switch in a circuit, we connect the output of the device that will switch on the transistor to the base of the transistor. The emitter will connect to ground of the circuit. And the collector will connect to the load that the transistor will turn on and the supply voltage of the circuit.
What is the best transistor for amplifier?
Best Transistors: BJTs
- #1 NPN – 2N3904. You can find most often NPN Transistors in low-side switch circuits.
- #2 PNP – 2N3906. For high-side switch circuits, you need a PNP style BJT.
- #3 Power – TIP120.
- #4 N-Channel (Logic Level) – FQP30N06L.
How is a transistor set up as an amplifier?
The figure below shows how the transistor is set up when it is connected in a circuit as an amplifier. In the figure given above, the input is connected in forward-biased and the output is connected in reverse-biased. The input signal is applied on the base-emitter junction and the output is taken through the load in emitter-collector junction.
How does a transistor amplify a weak signal?
Overall, the weak signal is thus amplified in the collector circuit. However, to work as an amplifier, the transistor has to work in the active region of the output voltage versus input voltage curve as seen in the figure below.
Why do we use CE configuration for transistors as amplifiers?
We usually employ CE configuration for transistors as amplifiers because it provides large values of current gain, voltage gain and power gain. Moreover, there is a phase-shift of 180 degrees between input and output. It implies the output signal will be an inverted amplified version of the signal given in the input.
What is amplifier and amplification?
What is Amplifier. Amplification is a process of increasing the signal strength by increasing the amplitude of a given signal with out changing its characteristics. The input signal may be a current signal, voltage signal or a power signal; amplifier will amplify the signal without changing its characteristics.