In what application is gallium arsenide used as a semiconductor material?

  1. In high-current rectifier circuits
  2. In high-power audio circuits
  3. In microwave circuits
  4. In very low-frequency RF circuits


Which of the following semiconductor materials contains excess free electrons?

  1. N-type
  2. P-type
  3. Bipolar
  4. Insulated gate


Why does a PN-junction diode not conduct current when reverse biased?

  1. Only P-type semiconductor material can conduct current
  2. Only N-type semiconductor material can conduct current
  3. Holes in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
  4. Excess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator


What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

  1. Insulator impurity
  2. N-type impurity
  3. Acceptor impurity
  4. Donor impurity


How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

  1. They are both low impedance
  2. An FET has lower input impedance
  3. An FET has higher input impedance
  4. They are both high impedance


What is the beta of a bipolar junction transistor?

  1. The frequency at which the current gain is reduced to 0.707
  2. The change in collector current with respect to base current
  3. The breakdown voltage of the base to collector junction
  4. The switching speed


Which of the following indicates that a silicon NPN junction transistor is biased on?

  1. Base-to-emitter resistance of approximately 6 to 7 ohms
  2. Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
  3. Base-to-emitter voltage of approximately 6 to 7 volts
  4. Base-to-emitter voltage of approximately 0.6 to 0.7 volts


What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

  1. Corner frequency
  2. Alpha rejection frequency
  3. Beta cutoff frequency
  4. Alpha cutoff frequency


What is a depletion-mode FET?

  1. An FET that exhibits a current flow between source and drain when no gate voltage is applied
  2. An FET that has no current flow between source and drain when no gate voltage is applied
  3. Any FET without a channel
  4. Any FET for which holes are the majority carriers


In Figure E6-1, what is the schematic symbol for an N-channel dual-gate MOSFET?

  1. 2
  2. 4
  3. 5
  4. 6
Circuit Diagram


In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

  1. 1
  2. 2
  3. 3
  4. 6
Circuit Diagram


Why do many MOSFET devices have internally connected Zener diodes on the gates?

  1. To provide a voltage reference for the correct amount of reverse-bias gate voltage
  2. To protect the substrate from excessive voltages
  3. To keep the gate voltage within specifications and prevent the device from overheating
  4. To reduce the chance of static damage to the gate