Assertion: Base in transistor is made very thin as compared to collector and emitter regions.
Reason: Due to thin base power gain and voltage gain is obtained by a transistor.

Options

A. If both the assertion and reason are true and reason is a true explantion of the assertion.
B. If both the assertion and reason are true but the reason is not true the correct explantion of the assertion.
C. If the assertion is true but reason false
D. If both the assertion and reason are false.

Answer

A

Explanation

In a transistor, the base is made extermely thin to reduce the combinations of holes and electrons. Under this conditions, most of the holes (or electrons) arriving from the emitter diffuses across base and reach the collector. hence, the collector current, is almost equal to base the emitter current, the base current being comparatively much smaller. This is the main reason that power gain and voltage gain are obtained by a transistor. if the base region was made quite thick, then majority of carriers form emitter will combine with the carriers in the base and only small number of carriers will reach the collector, so there would be little collector current and the purpose of transistor would be defeated.