Draw a circuit diagram of an n-p-n transistor with its emitter-base junction forward biased and base-collector junction reverse biased. Briefly describe its working. Explain how a transistor in active states exhibits a low resistance at its emitter-base junction and high resistance at its base-collector junction.

n-p-n transistor with its emitter -base junction forward biased and base collector junction reversed bias. Here, Emitter-base junction is forward biased and collector base junction is reverse biased. The voltage across the device causes electrons from emitter to flow to the collector. Electrons pass through the p-type lightly doped base region and some of the electrons recombine with holes, therefore collector current is less than that of emitter current. Emitter current, base current and collector current can be related by: Emitter current = Base current + collector current. In active mode of transistor emitter-base junction is forward biased and collector base junction is reversed biased. When transistor operates in this mode, collector current increases linearly with the increase in base current. That's why in active state it exhibits low resistance at emitter base and high resistance at its base -collector.