Question

The output voltage of a trans resistance amplifier has been found to increase by 20% when the 1 ka load resistance is disconnected. Find the value of the amplifier output resistance. \text { For the amplifier in Figure } 4(\mathrm{~b}) \text {, you are given that: } r_{s}=1 \mathrm{k} \Omega, R_{1}=64 \mathrm{k} \Omega, R_{2}=10 \mathrm{k} \Omega \text {, } R_{c}=6 \mathrm{k} \Omega, R_{E}=2 \mathrm{k} \Omega, R_{L}=2 \mathrm{k} \Omega, V_{c c}=+20 \mathrm{~V} \text { and } \beta=100 Draw the d.c. equivalent circuit and calculate the quiescent current Ica(assuming Var = 0.7 V).%3D Draw the a.c. equivalent circuit (assuming Xe =0 at signal frequency). Calculate the input resistance from the source, Ri, and the output resistance fromthe load, Ro (using Table 4b). Calculate the output voltage at the load, V. (using Table 4b).

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