A n-p-n transistor is connected in C - E configuration Collector supply is 8 V . The voltage drop across the load resistor of `800Omega` , connected to collector circuit is 0.8 volt . If `alpha = 25/26`

If input resistance of transistor is `200Omega` , then power gain is

Options

A. 1000 V
B. 1500 V
C. 2500 V
D. 3000 V

Answer

C

Explanation

`i_c=V_0/R_0=(0.8)/800=10^(-3)A`
Now `alpha=i_c/i_e,i_e=i_c/alpha=10^(-3)/(25//26)=26/25xx10^(-3)` amp.
Now `i_b=i_e-i_c=26/25xx10^(-3)-10^(-3)=4xx10^(-5)` amp
But `R_i=200Omega`
`:.` Input voltage `V_i-i_bR_i=4xx10^(-5)xx200`
`=8xx10^(-3)` volt
`:.` Voltage gain , `A_v=V_0/V_i=(0.8)/(8xx10^(-3))=100`
`:.` Power gain , `beta xx A_v = 25 xx100 = 2500`