If a change in base current does not change the collector current, the transistor amplifier is said to be
In a BJT, if the collector junction is reverse biased and the emitter junction is reverse - biased, it is said to operate in
On applying a positive voltage signal to the' base of a normally biased n-p-n CE transistor amplifier
Assertion (A): The process of giving proper supply voltages and resistances for obtaining the desired Q-point is called biasing.
Reason (R): In order to produce distortion free output in amplifier circuits, the supply voltages and resistances in the circuit must be suitably chosen.
Match List-I (Transistor parameters) with List-ll (Temperature effect) and select the correct answer using the codes given below the lists:
A. Base-emitter voltage (VBE)
B. Transistor current gain (β)
C. Reverse saturation current (Ico)
1. Independent of temperature
2. Decreases by 2.5 mV per oC
3. Increases with temperature
4. Increase by 7% per oC
For the transistor circuit shown below, the Q-point values are given as ICQ = 1 mA and VCEQ = 6V
If VBE (on) = 0.7 V, the values of the RB and Rc will be respectively
The collector resistance is:
Base current is,
For the transistor circuit shown below,β = 100 and VBE(on) = 0.7 V.
The transistor is working under
Let the transistor be operating under active region.
Applying KVL, we have:
In a collector-to-base CE amplifier circuit having Vcc = 12 V, Rc = 250 Ω , IB = 0.25 mA, β = 100 and VCEQ = 8 V, the stability factor will be approximately given by (neglect VBE)
For a coliector-to-base CE amplifier, stability factor is given by
A self-bias circuit (with an emitter resiistor) stabilizes the__________ of the circuit against variations in temperature and process parameters.
A self-bias circuit is used to establish a stable operating point in the self-biasing configuration. If Ic tends to increase, say, because Ico has risen as a result of an elevated temperature, the current in Re increases. As a consequence of the increase in voltage drop across Re, the base current is decreased. Hence, Ic will increase less than it would have been no self-biasing resistor Re.
In typical circuits, the stabilization factor S = (ΔICICO) is
For better stability of the circuit, stability factor S must be as small as possible.