Question

an ammeter is used in a series circuit with two 10.0ω resistors and a 9.0 v source. the ammeter has a resistance of 3.0ω. what could the voltmeter read over one of the resistors? o 3.9 v o 5.0 v o 0.39 v o not enough information.

Explanation:

Step1: Calculate total resistance

In a series - circuit, the total resistance $R_T$ is the sum of all resistances. Here, $R_1 = 10\Omega$, $R_2=10\Omega$ and $R_{A}=3\Omega$. So $R_T=10 + 10+3=23\Omega$.

Step2: Calculate current in the circuit

Using Ohm's law $I=\frac{V}{R}$, where $V = 9V$ and $R = R_T = 23\Omega$. So $I=\frac{9}{23}\approx0.39A$.

Step3: Calculate voltage across one resistor

The voltage across a single $10\Omega$ resistor, say $R_1$, using $V_1 = IR_1$. Substituting $I=\frac{9}{23}A$ and $R_1 = 10\Omega$, we get $V_1=\frac{9}{23}\times10=\frac{90}{23}\approx3.9V$.

Answer:

3.9 V