A transmission line has an input voltage of 0.4 volts and a decibel voltage gain of 18.6 decibels. Find the output voltage.

3.4 volts

Step-by-step explanation:

For voltage gain, the number of decibels is 20 times the base-10 logarithm of the actual gain. Then the ratio of output to input is ...

20·log (Vout/Vin) = 18.6

Vout/Vin = 10^ (18.6/20) ≈ 8.5114

So, the output voltage is ...

Vout = 8.5114·Vin = 8.5114·0.4 volts ≈ 3.4046 volts

The output voltage is about 3.4 volts.