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Required Information

Consider the circuit shown in the given figure.

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Find the values of the input impedance $R_{In},$ transistor amplifier in the given figure if $g_m=22ms,{}_O=75,r_O=100k,R_{\text{I}}=500,R_B=85k,R_L=12k,$ and $R_E=300.$

$R_{In}=k$

$r_o=\frac{del{v}_{CE}}{del{i}_C}=\frac{V_A+V_{CE}}{I_C}$~$=\frac{V_A}{I_C}$

${}_o=\frac{del{i}_C}{del{i}_B}$~$={}_F(1+\frac{V_{CE}}{V_A})$~$={}_F$

$r_{}=\frac{{}_o{V}_T}{I_C},g_m=\frac{{}_o}{r_{}}=\frac{I_C}{V_T}$~$=40*I_C$