- Fig. 4.28 shows the short circuit failures in a transistor. We shall discuss the circuit behaviour in each case.
(i) Collector-emitter short: Fig. 4.28 (i) shows a short between collector and emitter. The emitter diode is still forward biased, so we expect to see 0.7V at the base. Since the collector is shorted to the emitter, VC = VE = 0V.
(ii) Base -emitter short. Fig 4.28 (ii) shows a short between base and emitter. Since the base is now directly connected to ground, VB = 0. Therefore, the current through RB will be diverted to ground and there is no current to forward bias the emitter diode. As a result, the transistor will be cutoff and there is no collector current. So we will expect the collector voltage to be 12V.
(iii) Collector-base short: Fig. 4.28 (iii) shows a short between the collector and the base. In this case, the emitter diode is still forward biased so VB = 0.7V. Now, however, because the collector is shorted to the base, VC = VB = 0.7V.
Wilfykil answered the question on August 14, 2019 at 13:51
-
Fig. 4.27 shows the open circuit failures in a transistor. What will be the circuit behaviour in each case ?
(Solved)
Fig. 4.27 shows the open circuit failures in a transistor. What will be the circuit behaviour in each case ?
Date posted:
August 14, 2019
.
Answers (1)
-
A transistor has the following ratings: IC (max) = 500 mA and ßmax = 300.
(Solved)
A transistor has the following ratings: IC (max) = 500 mA and ßmax = 300. Determine the maximum allowable value of IB for the device.
Date posted:
August 14, 2019
.
Answers (1)
-
In a transistor, IB = 68 µA, IE = 30 mA and ß = 440.
(Solved)
In a transistor, IB = 68 µA, IE = 30 mA and ß = 440. Determine the a rating of the
transistor. Then determine the value of IC using both the a rating and ß rating of the transistor.
Date posted:
August 14, 2019
.
Answers (1)
-
A transistor is connected in common emitter (CE) configuration in which collector supply is 8V and the voltage drop across resistance RC connected in the...
(Solved)
A transistor is connected in common emitter (CE) configuration in which collector supply is 8V and the voltage drop across resistance RC connected in the collector circuit is 0.5V. The value of RC = 800 ohms. If α = 0.96, determine:
(i) collector-emitter voltage
(ii) base current
Date posted:
August 14, 2019
.
Answers (1)
-
For a transistor, ß = 45 and voltage drop across 1 kilo-ohm which is connected in the collector circuit is 1 volt.
(Solved)
For a transistor, β = 45 and voltage drop across 1 kilo-ohm which is connected in the collector circuit is 1 volt. Find the base current for common emitter connection.
Date posted:
August 14, 2019
.
Answers (1)
-
Find the a rating of the transistor shown in Fig. 4.20. Hence determine the value of IC using both a and ß rating of the...
(Solved)
Find the α rating of the transistor shown in Fig. 4.20. Hence determine the value of IC using both α and β rating of the transistor.
Date posted:
August 14, 2019
.
Answers (1)
-
Calculate IE in a transistor for which ß = 50 and IB = 20 µA.
(Solved)
Calculate IE in a transistor for which β = 50 and IB = 20 μA.
Date posted:
August 14, 2019
.
Answers (1)
-
Find the value of ß if;
(i) a = 0.9
(ii) a = 0.98
(iii) a = 0.99.
(Solved)
Find the value of β if;
(i) α = 0.9
(ii) α = 0.98
(iii) α = 0.99.
Date posted:
August 14, 2019
.
Answers (1)
-
Explain the Common Emitter Connection in transistors
(Solved)
Explain the Common Emitter Connection in transistors
Date posted:
August 14, 2019
.
Answers (1)
-
List the Transistor Connections or configurations
(Solved)
List the Transistor Connections or configurations
Date posted:
August 14, 2019
.
Answers (1)
-
A common base transistor amplifier has an input resistance of 20 ohms and output resistance of 100 kilo-ohms.
(Solved)
A common base transistor amplifier has an input resistance of 20 ohms and output resistance of 100 kilo-ohms. The collector load is 1 kilo-ohm. If a signal of 500 mV is applied between emitter and base, find the voltage amplification. Assume aac to be nearly one
Date posted:
August 14, 2019
.
Answers (1)
-
Explain how Transistor Circuit is used as an Amplifier
(Solved)
Explain how Transistor Circuit is used as an Amplifier
Date posted:
August 14, 2019
.
Answers (1)
-
Show in form of diagrams the Transistor Symbols
(Solved)
Show in form of diagrams the Transistor Symbols
Date posted:
August 14, 2019
.
Answers (1)
-
What is the Importance of transistor action?
(Solved)
What is the Importance of transistor action?
Date posted:
August 14, 2019
.
Answers (1)
-
Discuss on Transistor Action
(Solved)
Discuss on Transistor Action
Date posted:
August 14, 2019
.
Answers (1)
-
Which are the Facts about the Transistor?
(Solved)
Which are the Facts about the Transistor?
Date posted:
August 14, 2019
.
Answers (1)
-
Explain the Naming of Transistor Terminals
(Solved)
Explain the Naming of Transistor Terminals
Date posted:
August 14, 2019
.
Answers (1)
-
Over what range of input voltage will the Zener circuit shown in Fig. 3.68 maintain 30 V across 2000 O load, assuming that series resistance...
(Solved)
Over what range of input voltage will the Zener circuit shown in Fig. 3.68 maintain 30 V across 2000 Ω load, assuming that series resistance R = 200 Ω and Zener current rating is 25 mA ?
Date posted:
August 14, 2019
.
Answers (1)
-
What value of series resistance is required when three 10-watt, 10-volt, 1000 mA Zener diodes are connected in series to obtain a 30-volt regulated output...
(Solved)
What value of series resistance is required when three 10-watt, 10-volt, 1000 mA Zener diodes are connected in series to obtain a 30-volt regulated output from a 45 volt d.c. power source ?
Date posted:
August 14, 2019
.
Answers (1)
-
The circuit of Fig. 3.66 uses two Zener diodes, each rated at 15 V, 200 mA.
(Solved)
The circuit of Fig. 3.66 uses two Zener diodes, each rated at 15 V, 200 mA. If the circuit is connected to a 45-volt unregulated supply, determine:
(i) The regulated output voltage
(ii) The value of series resistance R
Date posted:
August 14, 2019
.
Answers (1)