An idealized ammeter is connected to a battery as shown in Fig. E25.28
. Find (a) the reading of the ammeter.

Verified step by step guidance

1. Identify the components in the circuit: a 12.0 V battery, a 16.8 Ω resistor, and a 12.0 Ω resistor connected in series with an ideal ammeter.
2. Calculate the total resistance in the circuit by adding the resistances of the two resistors: R_total = 16.8 Ω + 12.0 Ω.
3. Use Ohm's Law (V = IR) to find the total current in the circuit: I = V / R_total, where V is the voltage of the battery (12.0 V) and R_total is the total resistance calculated in the previous step.
4. Since the ammeter is ideal (it has zero resistance and does not affect the circuit), the current flowing through the ammeter is the same as the total current in the circuit.
5. The reading of the ammeter is the current calculated in the previous step.

Key Concepts

Ohm's Law

Ohm's Law states that the current (I) flowing through a conductor between two points is directly proportional to the voltage (V) across the two points and inversely proportional to the resistance (R) of the conductor. This relationship is expressed mathematically as V = I * R. Understanding this law is essential for analyzing electrical circuits and calculating current, voltage, and resistance.

Series and Parallel Circuits

In electrical circuits, components can be arranged in series or parallel. In a series circuit, the current is the same through all components, while the total resistance is the sum of individual resistances. In a parallel circuit, the voltage across each component is the same, and the total current is the sum of the currents through each path. Recognizing the configuration of the circuit is crucial for determining the total resistance and current flow.

Ammeter Functionality

An ammeter is a device used to measure the current flowing through a circuit. It is connected in series with the circuit components to ensure that all the current passes through it. Ideally, an ammeter has zero resistance to avoid affecting the circuit's operation. Understanding how to properly connect and interpret an ammeter's reading is vital for accurate current measurements in electrical circuits.