In a CE transistor amplifier, the audio signal voltage across the collector resistance of `2kOmega` is 2V. If the base resistance is `1kOmega` and the current amplification of the transistor is 100, the input signal voltage is ………..

Options

A. 0.1 V
B. 1.0 V
C. 1 mV
D. 10 mV

Answer

D

Explanation

10 mV
Output voltage `V_(o)=I_(c )R_(c )`
`therefore I_(c )=(V_(o))/(R_(c ))=(2)/(2xx10^(3))=10^(-3)A=1mA`
`beta=(I_(c ))/(I_(B)) rArr I_(B)=(I_(c ))/(beta)=(10^(-3))/(100)=10^(-5)A`
Input voltage `V_(i)=I_(B)R_(B)=10^(-5)xx1xx10^(3)=10^(-2)V`
`therefore V_(i)=10xx10^(-3)V=10mV`