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Physics · PYQ NEET UG 2018
हिन्दीIn the circuit shown in the figure, the input voltage \( V_i \) is \( 20\text{ V} \), \( V_{\text{BE}} = 0 \) and \( V_{\text{CE}} = 0 \). The values of \( I_{\text{B}} \), \( I_{\text{C}} \) and \( \beta \) are given by
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Correct answer · Option D
\( I_{\text{B}} = 40\text{ }\mu\text{A}, I_{\text{C}} = 5\text{ mA}, \beta = 125 \)
Explanation
Applying Kirchhoff's voltage law to the input circuit: \( I_{\text{B}} = \frac{V_i - V_{\text{BE}}}{R_{\text{B}}} = \frac{20 - 0}{500 \times 10^3} = 40\text{ }\mu\text{A} \). For the output circuit: \( I_{\text{C}} = \frac{V_{\text{CC}} - V_{\text{CE}}}{R_{\text{C}}} = \frac{20 - 0}{4 \times 10^3} = 5\text{ mA} \). Thus, \( \beta = \frac{I_{\text{C}}}{I_{\text{B}}} = \frac{5 \times 10^{-3}}{40 \times 10^{-6}} = 125 \).
