Answer:
Part A)
Since all of the resistors have equal resistance, hence for finding even only 1 branch It will be fine because current will be the same for all branches.
=> [tex]I = \frac{V}{R_{1} }[/tex]
=> [tex]I = \frac{30}{15}[/tex]
=> I = 2 A
Part B)
Equivalent resistance for parallel circuits is the sum of reciprocals of each resistor.
=> [tex]\frac{1}{R} = \frac{1}{R_{1}}+\frac{1}{R_{2}} +\frac{1}{R_{3}}[/tex]
=> [tex]\frac{1}{R} = \frac{1}{15}+ \frac{1}{15}+\frac{1}{15}[/tex]
=> [tex]\frac{1}{R} = \frac{3}{15}[/tex]
=> R = 15/3
=> R = 5 ohms
Part C)
I = V/R
Where I is current, V is voltage and R is the equivalent resistance
=> I = 30/5
=> I = 6 A
