14.1.8. Procedure for Finding Base Current

Try these first

1. 1.

   What is the link between base current and collector current in a BJT?

   Hint

   Think about the role of the transistor as an amplifier.

2. 2.

   How would you determine the collector-emitter voltage?

   Hint

   Focus on the voltage drops around the loop.

3. 3.

   What is the base current in a BJT circuit if I_C = 5mA and β = 100?

   • 0.05mA
   • 0.05A
   • 0.5mA

   Hint

   Consider how base current relates to collector current.

4. 4.

   True or False: The collector current in a BJT is always less than the base current.

   • True
   • False

   Hint

   Think about the role of a transistor.

5. 5.

   A transistor has an I_S of 50nA, and the base-emitter voltage is 0.75V. Calculate the base current I_B at room temperature (T=25°C).

   Hint

   Remember, use the thermal voltage of 25mV.

6. 6.

   In a linear circuit, if the collector-emitter voltage is observed to swing between 2V and 8V with corresponding collector currents of 10mA and 20mA, determine the slope of the load line.

   Hint

   Look for the change in current over the change in voltage.