Question

In a bipolar transistor at room temperature, the emitter current is doubled the voltage across its base emitter junction_________

(a) doubles

(b) halves

(c) increase by about 20mV

(d) decreases by about 20mV

I had been asked this question in a national level competition.

The above asked question is from Biasing Parameters in portion Small-Signal Low-Frequency AC models of Transistors of Electronic Devices & Circuits

Answer 1

Right choice is (c) increase by about 20mV

Explanation: The change in voltage with temperature can be found by, V(T) = 2.3m(∆T)VO . In a bipolar transistor at room temperature if the emitter current is doubled the voltage across its base emitter junction thereby doubles.