Question: 1 mv signal across this impedance is equal to?
Answer: From this, we see that dBmV expresses power in terms of voltage. 0 dBmV defines the power produced when a root mean square voltage of 1 mV is applied across a defined impedance, which is 75 ohms in the case of the cable industry. That is, 1 mV in a 75 ohm impedance is 13.33 nW, which we call 0 dBmV.