I think it’s when the sun explodes because since we need to the sun I think the human population will fall out. also a huge war, a meteoroid huge as the one that killed the dinosaurs comes down, there is so much ways on how the human population can stop growing. hope this help at least!
I thought you were going to ask for the resistance of the unknown
series resistor. Since you only want the equivalent resistance of the
circuit, you don't even need to know the resistance of the lamp.
I = E / R
Current through the circuit = (voltage of the battery) / (circuit resistance).
0.5 = (12) / R
Multiply each side by 'R' : (0.5) R = 12
Multiply each side by 2 : <em>R = 24 ohms</em>
(Since the resistance of the lamp is 10 ohms, the
unknown series resistor is the other 14 ohms.)
