Question

Find the current flowing out of the battery in the circuit. I = [?] A 9.0 V 30 ww 40 Ω www 50 Ω 20Ω 10Ω​

Answer 1

We need Net resistance

solve from right words

$\\ \rm\Rrightarrow R_1=20+10=30\Omega$

$\\ \rm\Rrightarrow \dfrac{1}{R_2}=\dfrac{1}{30}+\dfrac{1}{50}=\dfrac{5+3}{150}$

$\\ \rm\Rrightarrow R_2=\dfrac{150}{8}=18.75\Omega$

$\\ \rm\Rrightarrow \dfrac{1}{R_3}=\dfrac{1}{30}+\dfrac{1}{40}=\dfrac{4+3}{120}$

$\\ \rm\Rrightarrow R_3=\dfrac{120}{7}=17.14\Omega$

$\\ \rm\Rrightarrow R_{net}=17.14+18.75=35.89\Omega$

Use ohm's law

$\\ \rm\Rrightarrow I=\dfrac{V}{R}$

$\\ \rm\Rrightarrow I=\dfrac{9}{35.89}$

$\\ \rm\Rrightarrow I\approx 0.25A$