Bipolar transistors

What does the load line drawn on the output characteristics of a transistor amplifier represent?

  1. AThe transistor's maximum ratings
  2. BThe relationship between temperature and collector current
  3. CThe possible combinations of VCE and IC set by the load resistor and supply voltage
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Answer: C. The possible combinations of VCE and IC set by the load resistor and supply voltage

With a resistor RC and supply VCC on the collector side, VCE = VCC − IC × RC. This straight line drawn on the output characteristics is the load line, and the transistor operates somewhere on it. The intersection with the curve for the given IB is the operating point.

  • A. Maximum ratings are shown by curves such as the dissipation limit, which are separate from the load line.
  • B. The load line does not express a relationship with temperature.
  • C. Correct. It shows the combinations of VCE and IC that the external circuit allows.
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More Bipolar transistors questions

  1. Which value is closest to the maximum power efficiency of an ideal class B push-pull amplifier?
  2. In a circuit using a transistor as a switch, what is the main purpose of a resistor in series with the base?
  3. What is the difference between the DC current gain hFE and the small-signal current gain hfe?
  4. Which model represents the large-signal behavior of a bipolar transistor with two diodes and current sources?
  5. How does the current gain hFE of a bipolar transistor depend on collector current?