Is my Professor wrong? or am I wrong?

Bordodynov said:

Hello. Yes, I was embarrassed and mistaken. The incandescent lamp is not a current source, but only reduces the current change compared to the resistor.
I am sorry.
I realized this after I made a calculation on LTspice (as you can see). It just did not occur to me to correct myself. I was distracted by urgent work.
The calculation showed that the resistance of the lamp when connected without wires 7.2Ohm (P=20W), and with wires 6.82Ohm (P=16.34 W)

Click to expand...