# What would happen if both junctions of a BJT are forward biased or reverse biased?

## What would happen if both junctions of a BJT are forward biased or reverse biased?

Answer: If both junctions are reverse biased the transistor is switch off since the currents will be very small in the order of the reverse saturation current and the reverse is true that is the transistor will be switch on and saturated when the 2 junctions are forward biased.

### When a transistor is used as a switch it is biased in region?

Detailed Solution. When a transistor works as a switch it works in cut-off and saturation regions. In the cut-off state, both emitter-base junction and the collector-base junctions are reverse biased.

#### How can BJT be used as an amplifier?

Transistor Amplifier A transistor acts as an amplifier by raising the strength of a weak signal. The DC bias voltage applied to the emitter base junction, makes it remain in forward biased condition. Thus a small input voltage results in a large output voltage, which shows that the transistor works as an amplifier.

When both junctions of BJT are forward biased it operates in?

With both junctions forward biased, a BJT is in saturation mode and facilitates high current conduction from the emitter to the collector (or the other direction in the case of NPN, with negatively charged carriers flowing from emitter to collector). This mode corresponds to a logical “on”, or a closed switch.

When both junctions of BJT are forward biased it operates in *?

Detailed Solution

Emitter Base Junction Collector Base Junction Region of Operation
Forward bias Reverse bias Active
Forward bias Forward bias Saturation
Reverse bias Reverse bias Cut-off
Reverse Bias Forward Bias Inverse active

## Which transistor is used as switch?

Both PNP and NPN transistors can be utilized as switches. A basic terminal transistor can be handled differently from a signal amplifier by biasing both NPN and PNP bipolar transistors by an “ON / OFF” static switch. One of the main uses of the transistor to transform a DC signal “On” or “OFF” is solid-state switches.

### Which configuration of transistor is used as a switch?

Common-emitter configuration
The most commonly used transistor configuration for use as a switching device is the Common-emitter configuration. Explanation: Transistor: A semiconductor device used to amplify or switch electronic signals and electrical power is called a transistor.