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MHT CET · Physics · Semiconductors

A transistor is used as a common emitter amplifier with a load resistance \(2 \mathrm{k} \Omega\). The input resistance is \(150 \Omega\), Base current is changed by \(20 \mu \mathrm{A}\) which results in a change in collector current by \(1.5 \mathrm{~mA}\). The voltage gain of the amplifier is

  1. A \(1100\)
  2. B \(1000\)
  3. C \(900\)
  4. D \(12000\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(1000\)

Step-by-step Solution

Detailed explanation

The correct option is (B).
Concept: The voltage gain is given by
\(\beta=\frac{I_C}{I_B}=\frac{1.5 \mathrm{~mA}}{20 \mu \mathrm{A}}=75\)
And the voltage gain can be written as,
\(\frac{\mathrm{V}_0}{\mathrm{~V}_{\mathrm{i}}}=\beta \frac{\mathrm{R}_{\mathrm{L}}}{\mathrm{R}_{\mathrm{i}}}=75 \times \frac{2000}{150}=1000\)