1) Total resistance
the total resistance of a circuit with n resistors in parallel is given by
[tex] \frac{1}{R_{eq}} = \frac{1}{R_1}+ \frac{1}{R_2}+...+ \frac{1}{R_n} [/tex]
where [tex]R_i[/tex] are the single resistances.
In our circuit, we have 3 resistors of [tex]10.0 \Omega[/tex] each, so the total resistance of the circuit is given by
[tex] \frac{1}{R_{eq}}= \frac{1}{10 \Omega}+ \frac{1}{10 \Omega}+ \frac{1}{10 \Omega}= \frac{3}{10 \Omega} [/tex]
which means a total resistance of
[tex]R_{Eq} = \frac{10 \Omega}{3}=3.33 \Omega [/tex]
2) Current in the circuit
The current in the circuit can be found by using Ohm's law:
[tex]I= \frac{V}{R_{Eq}} [/tex]
where V is the voltage of the battery and Req is the total resistance we found before. By using V=15 V, we find
[tex]I= \frac{15 V}{3.33 \Omega}=4.5 A [/tex]
