Question 214: Semiconductors and Logic Gates

Question

A transistor is used in an amplifier circuit in common emitter mode. If the base current changes by 100 $$\mu$$A, it brings a change of 10 mA in collector current. If the load resistance is 2 k$$\Omega$$ and input resistance is 1 k$$\Omega$$, the value of power gain is x $$	imes$$ 104. The value of x is _____________.

Accepted Answer

Power gain $$ = {\left[ {{{\Delta {i_C}} \over {\Delta {i_B}}}} ight]^2} 	imes {{{R_o}} \over {{R_i}}}$$
$$ = {\left[ {{{{{10}^{ - 2}}} \over {{{10}^{ - 4}}}}} ight]^2} 	imes {2 \over 1}$$
$$ = 2 	imes {10^4}$$
$$ \Rightarrow x = 2$$

Semiconductors and Logic Gates

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