Lamp L1 is marked with "8V 16W" and lamp L2 is marked with "12V 36W". The two lamps are connected in series and connected in the circuit with voltage of U What is the maximum voltage to protect the circuit from damage?
∵ P = UI ∵ I lamp 1 = P lamp 1 / u lamp 1 = 16W △ 8V = 2ai lamp 2 = P lamp 2 / u lamp 2 = 36W △ 12V = 3A is the protection lamp 1, so the maximum current of the circuit is 2A. Calculate the resistance according to the words: ∵ R = u & sup2; ∵ P ∵ r lamp 1 = (8V) & sup2; ∵ 16W = 4Ω; R lamp 2 = (12V) & sup2; ∵ 36W = 4Ω ∵ lamp 1 is connected in series with lamp 2 ∵ r total = R lamp 1 +
As the circuit shown in the figure, to make bulb L1 and L2 form a parallel circuit, the______ .
In the circuit shown in the figure, when the switch S1 is disconnected and the switches S2 and S3 are closed, the bulbs L1 and L2 are connected in parallel