Electronic Devices - BJT and FET Frequency Response - Discussion

Discussion Forum : BJT and FET Frequency Response - General Questions (Q.No. 12)
12.
The input power to a device is 10,000 W at 1000 V. The output power is 500 W, and the output impedance is 100 . Find the voltage gain in decibels.
–30.01 dB
–20.0 dB
–13.01 dB
–3.01 dB
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
8 comments Page 1 of 1.

Abbasi said:   4 years ago
@Ridhi.

By using p= v^2/R formula.

RIDHI said:   5 years ago
How to find power gain in dbs and input impedance? can anyone explain me?

Mae said:   6 years ago
Po = Vo^2/R.

Where:
Po = 500 W.
R = 100 ohms.
Let Vo = x.

500=x^2/100.
x=Vo=223.607 V.

Av = Vo/Vi.

where:
Vo = 223.607 V.
Vi = 1000 V.

223.607/1000.
Av = 0.223.

AdB = 20logAv.

Where:
Av = 0.223.

20log(0.223).
AdB = -13.01.
(2)

Ejay said:   7 years ago
Av=Vin/Vout, Solve for Vout using P=V^2/R, 500=V^2/100, Vout=223.6V,
Remeber: Vdb=20log(av), Vdb=20log(223.6/1000)= -13.01db

Chinnu said:   7 years ago
Av = po * pi.
= 500 * 10000 = 1 * 20.

Av = 10log(1*20),
= -13.21db.

Kaviraj meena said:   9 years ago
Nice, thanks @Sanjay.

Sanjay said:   10 years ago
A power = Po/Pi.

Gain in db = 10log(Ap).

Sumit said:   1 decade ago
Here, which formula we can apply to solve this problem?

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