AA Chapter 3 - Transistor

The base current (I_B), emitter current (I_E) and collector current (I_C) of a transistor are related to each other by the formula"

• I_B = I_C + I_E.

• I_C = I_E + I_B.

• I_C = I_E - I_B.

• I_E = I_C - I_B.

A transistor has a collector current of 10 mA and β of 80. Calculate the emitter current.

• 0.125 mA.

• 9.875 mA.

• 10.125 mA.

• 800 mA.

When a transistor has a very low and an almost equal forward and reverse resistance between its emitter and base leads, the device effectively has

• an open emitter junction.

• a good collector junction.

• a shorted emitter junction.

• a shorted collector junction.

What is the application of common base transistor circuit?

• Amplification.

• Phase inversion.

• Impedance matching.

• Reduction of distortion.

Which one of the following statements is TRUE for a transistor operating in the cut-off region?

• Both the emitter-base and collector-base junctions are forward biased.

• Both the emitter-base and collector-base junctions are reverse biased.

• The emitter-base junction is forward biased and the collector-base junction is reversed-biased.

• The emitted-base junction is reverse biased and the collector-base junction is forward biased.

Determine the value of the collector current for a transistor with a beta of 100 and a base current of 30 µA.

• 0.3 µA.

• 30 µA.

• 3 mA.

• 3 MA.

A transistor has a collector current of 10 mA and a current gain of 50. Calculate the value of the base current.

• 0.2 mA.

• 40 mA.

• 60 mA.

• 500 mA.

Refer to Fig 1. The XY is called the

• Load line.

• Power line.

• Biasing line.

• Quiescent line.

Refer to Fig 2. Which one of the following groups of resistors provides a voltage divider bias for the circuit.

• Resistors R₁ and R₂.

• Resistors R₁ and R₃.

• Resistors R₃ and R₄.

• Resistors R₂ and R₄.

State 3 parts of the operating region of a transistor in DC biasing.

• Active region, cut-off region and saturation region.

• Active region, passive region and cut-off region.

• Active region, turn on region and cut-off region.

• Active region, forward bias region and reverse bias region.