Resistor Heat Dissipation (with imaginary numbers)

AI Thread Summary
To calculate heat dissipation in a circuit with complex numbers, the magnitude of the current and the real part of the impedance are used. The current I is given as (3 + 4j) Amps, leading to a magnitude |I| of 5 Amps. The real part of the impedance Z is 2 Ohms. The heat dissipated can be calculated using the formula P = (|I|^2) * Re(Z), resulting in P = 50 W. The discussion confirms the approach to calculating power dissipation in circuits with complex impedances.
derek88
Messages
12
Reaction score
1
Friends:

I am wondering about heat dissipation when you have imaginary numbers.

Lets say a current I = (3 + 4j) Amps is going through an impedance Z = (2 + 3j) Ohms. What is the amount of heat dissipated by the impedance?

I think that you take the magnitude of the current, |I| = 5 Amps, and then find the heat dissipated by only the real part of the impedance, Re(Z) = 2. The heat dissipated would be P = (5^2)*2 = 50 W.

Is this correct?

Note: This is not a homework question. This is something I just wanted to verify.
 
Science news on Phys.org
The RMS power is:
P_{RMS}={|I|^2 \over 2} |Z|
 
Last edited:
I need to calculate the amount of water condensed from a DX cooling coil per hour given the size of the expansion coil (the total condensing surface area), the incoming air temperature, the amount of air flow from the fan, the BTU capacity of the compressor and the incoming air humidity. There are lots of condenser calculators around but they all need the air flow and incoming and outgoing humidity and then give a total volume of condensed water but I need more than that. The size of the...
Thread 'Why work is PdV and not (P+dP)dV in an isothermal process?'
Let's say we have a cylinder of volume V1 with a frictionless movable piston and some gas trapped inside with pressure P1 and temperature T1. On top of the piston lay some small pebbles that add weight and essentially create the pressure P1. Also the system is inside a reservoir of water that keeps its temperature constant at T1. The system is in equilibrium at V1, P1, T1. Now let's say i put another very small pebble on top of the piston (0,00001kg) and after some seconds the system...
Back
Top