Question

section 5 - 3 current in a series circuit

1. what is the current through each resistor in a series circuit if the total voltage is 12 v and the total resistance is 120 ω?
2. the current from the source in figure 5 - 69 is 5 ma. how much current does each milliammeter in the circuit indicate?
3. show how to connect a voltage source and an ammeter to the pc board in figure 5 - 64 to measure the current in r₁. which other resistor currents are measured by this setup?

problems 167

Explanation:

Step1: Recall Ohm's Law

Ohm's Law is $I=\frac{V}{R}$, where $I$ is current, $V$ is voltage and $R$ is resistance.

Step2: Substitute values for problem 15

Given $V = 12V$ and $R=120\Omega$. Then $I=\frac{12}{120}=0.1A$.

Step3: Understand series - circuit current property for problem 16

In a series circuit, the current is the same throughout. So if the source current is $5mA$, each milliammeter in the circuit indicates $5mA$.

Step4: Analyze ammeter connection for problem 17

In a series circuit, when an ammeter is connected to measure the current in one resistor, it measures the current of the whole circuit. So if an ammeter is connected to measure the current in $R_1$, it also measures the currents in $R_2$ and $R_3$.

Answer:

1. $0.1A$
2. $5mA$
3. The currents in $R_2$ and $R_3$ are also measured.