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What are the conditions of a transistor problem?
Fig. 4 Fig. 8.20 shows the conditions of the problem. Q11. For a transistor, β = 45 and voltage drop across 1kΩ which is connected in the collector circuit is 1 volt. Find the base current for common emitter connection.
What should the AC of a transistor be?
Assume α ac to be nearly one. Fig.1 shows the conditions of the problem. Here the output resistance is very high as compared to input resistance, since the input junction (base to emitter) of the transistor is forward biased while the output junction (base to collector) is reverse biased.
What is the output resistance of a transistor?
Here the output resistance is very high as compared to input resistance, since the input junction (base to emitter) of the transistor is forward biased while the output junction (base to collector) is reverse biased. Fig. 1 Q2. In a common base connection, I E = 1mA, I C = 0.95mA.
Why is there no base current in a transistor?
Since the collector diode is not forward biased, it is OFF and there can be neither collector current nor base current. collector leads of the transistor will be 12V. Fig. 11 (ii) shows an open base failure in a transistor. Since the base is open, there can be no base current so that the transistor is in cut-off.
How to calculate the current of a transistor?
A voltage of 5 V is applied between collector and base. With collector positive, a current of 0.2 μA flows. When the base is disconnected and the same voltage is applied between collector and emitter, the current is found to be 20 μA. Find α, I E and I B when collector current is 1 mA.
How to troubleshoot transistor ( BJT ) circuits correctly?
For Example if supply voltage V CC = 20 V, and a display on the meter for collector-emitter current V CE is may be 1 to 2 V or 18 to 20 V then undoubtedly it is an an abnormal outcome. Unless, otherwise this is intentionally designed the network and connections must be inspected.
What happens when the base of a transistor is open?
Since the base is open, there can be no base current so that the transistor is in cut-off. Therefore, all the transistor currents are 0A. In this case, the base and collector voltages will both be at 12V. Fig. 11 (iii) shows an open collector failure in a transistor. In this case, the emitter diode is still ON, so we expect to see 0.7V at the base.