Are all the children of a suckling woman considered brothers to the strange child whom their mother had breastfed, or just to the one who had suckled with him?

All the children of the woman who had suckled a strange child are considered his/her brothers and sisters.

Is it permissible for one to masturbate in order not to commit fornication?

This is called committing the milder of the two evils such as eating a carcass in fear of death, and this happens when committing fornication is very likely to occur.

What is the ruling on giving Zakah(obligatory charity)to one`s relatives?

It is impermissible to pay Zakah to one`s origins( parents and grandparents) because providing for them is an obligation on their branches (sons and daughters )if they were poor, but it is permissible to give some of the Zakah money to relatives whose provision isn`t due on the giver of the Zakah.

What is the ruling of Sharia on charging one`s mobile from the plug of the university`s lecture room?