# The Common Base Configuration MCQ’s

This set of Electronic Devices & Circuits Multiple Choice Questions & Answers (MCQs) focuses on “The Common Base Configuration”.

1. The value of αac for all practical purposes, for commercial transistors range from_________

a) 0.5-0.6

b) 0.7-0.77

c) 0.8-0.88

d) 0.9-0.99

2. A transistor has an I_{C} of 100mA and I_{B} of 0.5mA. What is the value of αdc?

a) 0.787

b) 0.995

c) 0.543

d) 0.659

3. The AC current gain in a common base configuration is_________

a) -∆I_{C}/∆I_{E}

b) ∆I_{C}/∆I_{E}

c) ∆I_{E}/∆I_{C}

d) -∆I_{E}/∆I_{C}

4. In CB configuration, the value of α=0.98A. A voltage drop of 4.9V is obtained across the resistor of 5KΩ when connected in collector circuit. Find the base current.

a) 0.01mA

b) 0.07mA

c) 0.02mA

d) 0.05mA

5. Determine the value of emitter current and collector current of a transistor having α=0.98 and collector to base leakage current I_{C}BO=4µA. The base current is 50µA.

a) 1.5mA

b) 3.7mA

c) 2.7mA

d) 4.5mA

6. The relation between α and β is _________

a) β=α/(1-α)

b) α= β/(1+β)

c) β=α/(1+α)

d) α= β/(1- β)

7. The emitter current I_{E} in a transistor is 3mA. If the leakage current I_{C}BO is 5µA and α=0.98, calculate the collector and base current.

a) 3.64mA and 35µA

b) 2.945mA and 55µA

c) 3.64mA and 33µA

d) 5.89mA and 65µA

8. The negative sign in the formula of amplification factor indicates_________

a) that I_{E} flows into transistor while I_{C} flows out it

b) that I_{C} flows into transistor while I_{E} flows out it

c) that I_{B} flows into transistor while I_{C} flows out it

d) that I_{C} flows into transistor while I_{B} flows out it

9. A transistor has an I_{E} of 0.9mA and amplification factor of 0.98. What will be the I_{C}?

a) 0.745mA

b) 0.564mA

c) 0.236mA

d) 0.882mA

10. The collector current is 2.945A and α=0.98. The leakage current is 2µA. What is the emitter current and base current?

a) 3mA and 55µA

b) 2.945mA and 55µA

c) 3.64mA and 33µA

d) 5.89mA and 65µA

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