Transistors

When transistors are used in digital circuits they usually operate in the:

• active region

• breakdown region

• saturation and cutoff regions

• linear region

1. A bipolar junction transistor has beta=250 and base current=10micro ampere. What is the collector current?

• 500 µ A

• 500 mA

• 2.5 mA

• 50 mA

A current ratio of I_C/I_E is usually less than one and is called:

• beta

• theta

• alpha

• omega

With the positive probe on an NPN base, an ohmmeter reading between the other transistor terminals should be

• open

• infinite

• low resistance

• high resistance

In a C-E configuration, an emitter resistor is used for:

• stabilization

• ac signal bypass

• collector bias

• higher gain

Voltage-divider bias provides:

• an unstable Q point

• a stable Q point

• a Q point that easily varies with changes in the transistor's current gain

• a Q point that is stable and easily varies with changes in the transistor’s current gain

To operate properly, a transistor's base-emitter junction must be forward biased with reverse bias applied to which junction?

• collector-emitter

• collector-base

• base-emitter

The ends of a load line drawn on a family of curves determine:

• saturation and cutoff

• the operating point

• the amplification factor

If V_CC = +18 V, voltage-divider resistor R₁ is 4.7 k ohms, and R₂ is 1500 ohms, what is the base bias voltage?

• 8.7

• 4.35

• 2.90

The C-B configuration is used to provide which type of gain?

• voltage

• current

• power