42 Lecture
PHY301
Midterm & Final Term Short Notes
Collector Emitter Loop
The Collector Emitter Loop, or C-E Loop, is a fundamental concept in Bipolar Junction Transistor (BJT) circuits.
Important Mcq's
Midterm & Finalterm Prepration
Past papers included
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What is the voltage drop across the collector-emitter junction in a BJT when it is operating in the active region?
a. approximately zero
b. approximately 0.2 volts
c. approximately 0.6 volts
d. approximately the same as the supply voltage
Answer: c. approximately 0.6 volts
In a common emitter BJT configuration, which of the following currents flow in the collector-emitter loop?
a. only the collector current
b. only the base current
c. only the emitter current
d. both the collector and emitter currents
Answer: d. both the collector and emitter currents
What is the purpose of the collector resistor in a BJT circuit?
a. to limit the base current
b. to provide negative feedback
c. to stabilize the bias point
d. to provide a load for the transistor
Answer: d. to provide a load for the transistor
What is the typical value of the collector current in a BJT operating in the active region?
a. microamps
b. milliamps
c. amps
d. tens of amps
Answer: b. milliamps
Which of the following is true about the direction of the collector current in a PNP transistor?
a. it flows from the emitter to the collector
b. it flows from the collector to the emitter
c. it flows in both directions
d. it does not flow in a PNP transistor
Answer: a. it flows from the emitter to the collector
What is the direction of the voltage drop across the collector-emitter junction in a BJT operating in the active region?
a. positive on the collector and negative on the emitter
b. negative on the collector and positive on the emitter
c. positive on both the collector and emitter
d. negative on both the collector and emitter
Answer: b. negative on the collector and positive on the emitter
Which of the following is true about the direction of the base current in a BJT?
a. it flows from the emitter to the collector
b. it flows from the collector to the emitter
c. it flows in both directions
d. it does not flow in a BJT
Answer: b. it flows from the collector to the emitter
In a common base BJT configuration, which of the following currents flow in the collector-emitter loop?
a. only the collector current
b. only the base current
c. only the emitter current
d. both the collector and emitter currents
Answer: a. only the collector current
What is the typical value of the voltage drop across the base-emitter junction in a BJT operating in the active region?
a. approximately zero
b. approximately 0.2 volts
c. approximately 0.6 volts
d. approximately the same as the supply voltage
Answer: c. approximately 0.6 volts
Which of the following is true about the direction of the emitter current in a BJT?
a. it flows from the emitter to the collector
b. it flows from the collector to the emitter
c. it flows in both directions
d. it does not flow in a BJT
Answer: a. it flows from the emitter to the collector
Subjective Short Notes
Midterm & Finalterm Prepration
Past papers included
Download PDF
What is the collector-emitter loop?
The collector-emitter loop is the path that current takes through the collector and emitter terminals of a bipolar junction transistor (BJT) when the transistor is in active mode.
What is the significance of the collector-emitter loop?
The collector-emitter loop is significant because it determines the voltage gain and current gain of a BJT. It also determines the maximum power that can be dissipated by the transistor without causing damage.
What is the role of the collector-emitter loop in amplification?
The collector-emitter loop plays a critical role in amplification because it allows for small changes in the base current to produce large changes in the collector current. This allows the BJT to act as an amplifier.
What is the effect of increasing the collector resistance on the collector-emitter loop?
Increasing the collector resistance will decrease the slope of the collector-emitter loop, which will reduce the voltage gain of the BJT.
What happens if the collector-emitter loop is opened?
If the collector-emitter loop is opened, the BJT will not function as an amplifier because no current can flow through the transistor.
What is the effect of increasing the base current on the collector-emitter loop?
Increasing the base current will cause the collector current to increase, which will cause the collector-emitter loop to shift upward.
How does temperature affect the collector-emitter loop?
Temperature can affect the collector-emitter loop by changing the characteristics of the transistor. For example, an increase in temperature can cause the saturation current to increase, which will cause the collector-emitter loop to shift downward.
What is the significance of the slope of the collector-emitter loop?
The slope of the collector-emitter loop determines the voltage gain of the BJT. A steeper slope results in a higher voltage gain.
What is the effect of increasing the load resistance on the collector-emitter loop?
Increasing the load resistance will cause the collector-emitter loop to shift downward, which will reduce the voltage gain of the BJT.
How does the collector-emitter loop affect the stability of the BJT?
The stability of the BJT is affected by the shape and position of the collector-emitter loop. If the loop is unstable, the BJT may oscillate, which can cause distortion or even damage to the transistor.