Question

A sensor uses 2.1 ✕ 10-4 a of current when it is operated by a 3.0 v battery. what is the resistance of the radio circuit? assume that the battery voltage is constant, no matter what current is present.

Answer 1

We can calculate the resistance of the radio circuit by using Ohm's law:
$V=IR$
where
V is the voltage of the circuit
I is the current
R is the resistance

In this circuit, $V=3.0 V$ and $I=2.1 \cdot 10^{-4} A$. If we rearrange the previous equation and we use these data, we can calculate the resistance of the circuit:
$R= \frac{V}{I}= \frac{3.0 V}{2.1 \cdot 10^{-4}A}=1.43 \cdot 10^4 \Omega = 14.3 k\Omega$