Question

A germanium transistor with α=0.98 gives a reverse saturation current ICBO=10µA in a CB configuration. When it is used in CE configuration with a base current of 0.22µA, calculate the collector current.

(a) 0.9867mA

(b) 0.7654mA

(c) 0.51078mA

(d) 0.23456mA

The question was posed to me in examination.

My doubt is from The Common Emitter Configuration topic in portion Transistor Characteristics of Electronic Devices & Circuits

Answer 1

The correct option is (c) 0.51078mA

Easy explanation: Given, ICBO=10µA, α=0.98 and IB =0.22µA. IC=α/ (1-α) IB+ 1/(1-α) ICBO

0.01078+0.5=0.51078mA.