1. When two lamps are connected in series, connect the power supply, switch, light bulb A and light bulb B in turn from the positive electrode, and finally return to the negative electrode, as shown in the figure:

2. When two lamps are connected in parallel, the power supply and the switch are connected in turn from the positive pole, and from the switch branch, one returns to the negative pole through the bulb A and the other returns to the negative pole through the bulb B, as shown in the figure:

Extended data:

The characteristics of series circuit mainly include:

1. The current in all series components is the same current, and I always = L 1 = L2 = L3 =...= ln.

2. The total voltage of series elements is the sum of the terminal voltages of all elements, and u is always = U 1+U2+U3+...+UN.

The characteristics of parallel circuit mainly include:

1. The terminal voltages of all parallel components are the same.

2. The total current of the parallel circuit is the sum of the currents of all components. I is the total current, i 1, i2 and i3 are the current of element 1, 2,3 respectively, and i=i 1+i2+i3.