Question

A common emitter amplifier is designed with n-p-n transistor (α = 0.99). The input impedance is 1 kΩ and the load is 10 kΩ. The voltage gain will be ______

Options

• 9.9

• 99

• 990

• 9900

Answer 1

A common emitter amplifier is designed with n-p-n transistor (α = 0.99). The input impedance is 1 kΩ and the load is 10 kΩ. The voltage gain will be 990.

Explanation:

Voltage gain = β x Resistance gain

β = `alpha/(1 - alpha) = 0.99/((1 - 0.99)) = 99`

∴ Resistance gain = `(10 xx 10^3)/(10^3) = 10`

⇒ Voltage gain = 99 × 10 = 990