Question

A circuit with a battery, a 3 Ω resistor, a 21 Ω resistor, and a 27 Ω resistor in parallel. The total voltage is the system is 1.0 V. What is the current through the battery?

Answer 1

0.42A

Step-by-step explanation

The current through the battery is the total current circulating through the circuit. To find it, first, we have to find the equivalent resistance between the three parallel resistors,

`R_(eq)=3\Omega\parallel21\Omega\parallel27\Omega=(1)/((1)/(3\Omega)+(1)/(21\Omega)+(1)/(27\Omega))\approx2.39\Omega`

Now, applying Ohm's law and knowing that the voltage across the battery is 1.0V, we can find the current through the circuit,

`I=(V)/(R)=(1.0V)/(2.39\Omega)=0.42A`

Hence, the current through the battery is 0.42A