Problems in three phase AC circuit experiment We have a question in our experiment, which is how the brightness of the three light bulbs will change when a live wire breaks suddenly when the triangle is connected, and why?

Problems in three phase AC circuit experiment We have a question in our experiment, which is how the brightness of the three light bulbs will change when a live wire breaks suddenly when the triangle is connected, and why?

One remains unchanged and the two lights connected to the open phase dim

Calculation of voltage and current
The two resistors are marked with "20 ohm, 1A", "15 ohm, 1.2A". If they are connected in parallel, how much voltage should be applied at both ends of the circuit? What is the maximum current allowed to pass in the trunk circuit? If they are connected in series, how much voltage should be applied at both ends of the circuit?

The two resistors are marked with "20 Ω, 1A" and "15 Ω, 1.2A". If they are connected in parallel, the voltage applied at both ends can not be greater than? U1 = r1i1 = 20 Ω * 1A = 20V; U2 = R2 * I2 = 15 Ω * 1.2A = 18V; U = 18V is used to protect electrical appliances. What is the maximum current allowed in the trunk? I = I1 '+ I2 = u / R1