ground is always considered at 0 Volt?
Will this bulb glow and why?
No as there is no potential difference to allow current to flow.
Welcome to PF :)
Generally yes its the 0V.
umm just trying to decypher your diagram it appears to show the 2 positive terminals connected to the lamp and the 2 negative teminals connected together.
In this case the lamp WONT glow as there can be no current flow
your actual subject question doesnt have anything to do with the
circuit diag you have posted and the question you asked about current flow
the 2 questions are not related :)
and if one source offers 5 volt and other offers 15 volt ? will bulb glow?
because now there is a potential difference as it's called voltages!
Yes, because there is a potential difference then.
Ground can be any voltage you like as long as you state all other voltages relative to ground. So you could call ground 100V and state all the other voltages relative to this if you wanted... there just isn't much point in doing so.
because i tested this thing with a software livewire 1.1 . the bulb glows if one battery provides 15 v and other 5v. And as there is a difference of 10 volts.
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