What is the ruling on wiping the white area behind the ears instead of wiping the head?
The obligation in ablution is to wipe some of the head; it is not a condition to wipe all of it. Wiping the white area behind the ears suffices for that. And Allah the almighty knows best.
What is the ruling on one who feels drops of urine falling during ablution?
If he is certain that urine is exiting from him during ablution, then his ablution is invalidated. He must remove the impurity from his clothes and body and repeat the ablution.
However, if what he feels regarding urine exiting is merely doubt or illusion, then ablution is not invalidated by doubt and illusion. He should not pay attention to it, and it is not permissible for him to follow the doubt and whispers that corrupt his religion. And Allah the almighty knows best.
Who should pay the Zakah (obligatory charity) from the orphan`s money?
His/her guardian, and if the latter fails to do so, then the orphan himself/herself is obliged to pay the Zakah once he/she reaches puberty, and is capable of handling his/her own affairs. And Allah Knows Best.
Does the time of Fajr (dawn) prayer start after the first Athaan (call for prayer), or the second one?
All perfect praise be to Allah,The Lord of The Worlds The time of Fajr prayer starts after the second Adhan. And Allah Knows Best.