Which of the following biasing techniques are affected by thermal runaway?

the biasing technique is identified by temperature effect

Thermal stability is dependent on thermal runaway which is_________

an uncontrolled positive feedback

an uncontrolled negative feedback

Thermal stability can be obtained by_________

decreasing current at collector

Explore topic-wise MCQs in Electronic Devices and Circuits.

This section includes 7 Mcqs, each offering curated multiple-choice questions to sharpen your Electronic Devices and Circuits knowledge and support exam preparation. Choose a topic below to get started.

1.	Which of the following biasing techniques are affected by thermal runaway?
A.	self bias
B.	collector to base bias
C.	fixed bias
D.	the biasing technique is identified by temperature effect
Answer» D. the biasing technique is identified by temperature effect

Discussion

2.	Thermal stability is dependent on thermal runaway which is_________
A.	an uncontrolled positive feedback
B.	a controlled positive feedback
C.	an uncontrolled negative feedback
D.	a controlled negative feedback
Answer» B. a controlled positive feedback

Discussion

3.	Thermal stability can be obtained by_________
A.	shifting operating point
B.	increasing power supply
C.	heat sink
D.	decreasing current at collector
Answer» D. decreasing current at collector

Discussion

4.	The total thermal resistance of a power transistor and heat sink is 20 C/W. The ambient temperature is 25 C and (T_J)MAX=200 C. If V_CE=4V, find the maximum collector current that the transistor can carry without destruction. What will be the allowed value of collector current if ambient temperature rises to 75 C?
A.	3.67A
B.	7.56A
C.	2.19A
D.	1.56A
Answer» E.

Discussion

5.	The total thermal resistance of a power transistor and heat sink is 20 C/W. The ambient temperature is 25 C and (T_J)MAX=200 C. If V_CE=4V, find the maximum collector current that the transistor can carry without destruction.
A.	3.67A
B.	7.56A
C.	2.19A
D.	4.16A
Answer» D. 4.16A

Discussion

6.	A silicon power transistor is operated with a heat sink H_S-A=1.5 C/W. The transistor rated at 150W (25 C) has H_J-C=0.5 C/W and the mounting insulation has HC-S=0.6 C/W. What maximum power can be dissipated if the ambient temperature is 40 C and (T_J)MAX=200 C?
A.	70.6W
B.	61.5W
C.	37.8W
D.	56.9W
Answer» C. 37.8W

Discussion

7.	For a given transistor, the thermal resistance is 8 C/W and for the ambient temperature T_A is 27 C. If the transistor dissipates 3W of power, calculate the junction temperature (T_J).
A.	51 C
B.	27 C
C.	67 C
D.	77 C
Answer» B. 27 C

Discussion

Explore topic-wise MCQs in Electronic Devices and Circuits.

Which of the following biasing techniques are affected by thermal runaway?

Thermal stability is dependent on thermal runaway which is_________

Thermal stability can be obtained by_________

The total thermal resistance of a power transistor and heat sink is 20 C/W. The ambient temperature is 25 C and (TJ)MAX=200 C. If VCE=4V, find the maximum collector current that the transistor can carry without destruction.

A silicon power transistor is operated with a heat sink HS-A=1.5 C/W. The transistor rated at 150W (25 C) has HJ-C=0.5 C/W and the mounting insulation has HC-S=0.6 C/W. What maximum power can be dissipated if the ambient temperature is 40 C and (TJ)MAX=200 C?

For a given transistor, the thermal resistance is 8 C/W and for the ambient temperature TA is 27 C. If the transistor dissipates 3W of power, calculate the junction temperature (TJ).

The total thermal resistance of a power transistor and heat sink is 20 C/W. The ambient temperature is 25 C and (T_J)MAX=200 C. If V_CE=4V, find the maximum collector current that the transistor can carry without destruction.

A silicon power transistor is operated with a heat sink H_S-A=1.5 C/W. The transistor rated at 150W (25 C) has H_J-C=0.5 C/W and the mounting insulation has HC-S=0.6 C/W. What maximum power can be dissipated if the ambient temperature is 40 C and (T_J)MAX=200 C?

For a given transistor, the thermal resistance is 8 C/W and for the ambient temperature T_A is 27 C. If the transistor dissipates 3W of power, calculate the junction temperature (T_J).