Analog Electronics - Practice Test

[#266] Which of the following holds FALSE for BJTs?

(A) The quantity beta (β) provides an important relationship between the base and collector currents, and is usually between 50 and 400

(B) The impedance between terminals of a forward-biased junction is always relatively large, whereas the impedance between terminals of a reverse-biased junction is usually quite small

(C) The dc beta is defined by a simple ratio of dc currents at an operating point

(D) The quantity alpha (α) relates the collector and emitter currents and is always close to one

Correct Answer

(B) The impedance between terminals of a forward-biased junction is always relatively large, whereas the impedance between terminals of a reverse-biased junction is usually quite small

[#267] In order to ensure that the output voltage of an op-amp is zero, when both its inputs are grounded

(A) Internal negative feedback is used

(B) An external offset balancing circuit is used at the input terminals

(C) The currents incident at the output node are carefully designed

(D) The totem-pole output transistors are designed to have exactly equal cut in voltages

Correct Answer

(B) An external offset balancing circuit is used at the input terminals

[#268] If α = 0.98, I CO = 6 µA and I B = 100 µA for a transistor, then the value of I C will be

(A) 2.3 mA

(B) 3.1 mA

(C) 4.6 mA

(D) 5.2 mA

Correct Answer

(D) 5.2 mA

[#269] The circuit of figure uses an ideal Op-Amp for small positive values of V in , the circuit works as

(A) A half wave rectifier

(B) A differentiator

(C) A logarithmic amplifier

(D) An exponential amplifier

Correct Answer

(C) A logarithmic amplifier

[#270] For a common emitter. BJT configuration with collector terminal resistance R, the slope of the D.C. load line can be given by:

(A) 1

(B) R

(C) 1/R

(D) -1/R

Correct Answer

(D) -1/R

Analog Electronics - Study Mode

[#266] Which of the following holds FALSE for BJTs?

Correct Answer

[#267] In order to ensure that the output voltage of an op-amp is zero, when both its inputs are grounded

Correct Answer

[#268] If α = 0.98, I CO = 6 µA and I B = 100 µA for a transistor, then the value of I C will be

Correct Answer

[#269] The circuit of figure uses an ideal Op-Amp for small positive values of V in , the circuit works as

Correct Answer

[#270] For a common emitter. BJT configuration with collector terminal resistance R, the slope of the D.C. load line can be given by:

Correct Answer