Question

Answer this question

Answer 1

in the first case current will flow up to down
in the second case current will flow up
in the second case bulb will not glows
yes brightness of the bulb depends on the current flowing through the conductor

Answer 2

In the first case, current can be fluctuated and it can flow up or down according to the current supply.

But in the second case, current can flow down and you cannot find the brightness on the bulb.

Brightness of the bulb is depends on the current flow and you need to check the conductor of the bulbs to detect the current flow.