Four 60 W, 230 V bulbs are connected between the phase and the neutral as shown in the diagram. Line voltage is 230 V.
How are the bulbs B3 and B4 and B1 and B2 connected?
B3, B4 are in series
B1, B2 are in parallel
The current flowing through B3 is equal to that flowing through the B4. Therefore, B3 and B4 are in series.
The voltage across B1 and B2 are equal since they have two common points. Hence, they are in parallel connection.