Hey!
I built a circuit with a 5V power supply and a 300 ohms resistor. With a multimeter I did the measurements of resistance, voltage and current across the resistor. The values was:
R = 298 ohms
E = 4.94 V
I = 16 mA
So I made the calcs to obtain the power dissipated by the resistor:
P = EI = 4.94 * .016 = 79 mW
P = E²/R = 4.94² / 298 = 81.9 mW
P = I²*R = .016² * 298 = 76.3 mW
My question is: Why there are differences between the power results? It's because of the lack of precision in measurements, the increase of resistor's resistance when powered or a combination of both?
I built a circuit with a 5V power supply and a 300 ohms resistor. With a multimeter I did the measurements of resistance, voltage and current across the resistor. The values was:
R = 298 ohms
E = 4.94 V
I = 16 mA
So I made the calcs to obtain the power dissipated by the resistor:
P = EI = 4.94 * .016 = 79 mW
P = E²/R = 4.94² / 298 = 81.9 mW
P = I²*R = .016² * 298 = 76.3 mW
My question is: Why there are differences between the power results? It's because of the lack of precision in measurements, the increase of resistor's resistance when powered or a combination of both?