Electrical Circuits This section focuses on the analysis of electrical circuits, which is fundamental in understanding the behavior of electrical systems. Stude...
This section focuses on the analysis of electrical circuits, which is fundamental in understanding the behavior of electrical systems. Students will explore both series and parallel circuits, as well as the principles of voltage dividers and potential dividers.
In a series circuit, components are connected end-to-end, so the same current flows through each component. The total resistance Rtotal in a series circuit is the sum of the individual resistances:
Problem: Calculate the total resistance of a series circuit with three resistors: R1 = 4Ω, R2 = 6Ω, and R3 = 10Ω.
Solution:
In contrast, in a parallel circuit, all components are connected across the same two points, leading to multiple paths for the current. The total resistance Rtotal in a parallel circuit can be calculated using the formula:
1/Rtotal = 1/R1 + 1/R2 + 1/R3
A voltage divider is a simple circuit that turns a large voltage into a smaller one. It consists of two resistors in series. The output voltage Vout across one of the resistors can be calculated as:
Vout = Vin * (R2 / (R1 + R2))
Electromotive force (EMF) is the voltage provided by a source, such as a battery, when no current is flowing. However, when a circuit is closed and current flows, the terminal voltage Vterminal can be affected by the internal resistance r of the source:
Vterminal = EMF - I * r
Electrical measurements are crucial for analyzing circuits. Ammeters are used to measure current, while voltmeters measure voltage. It is important to connect these devices correctly: ammeters must be connected in series, and voltmeters in parallel.
Problem: If an ammeter reads 2A and the internal resistance of the battery is 1Ω, what is the terminal voltage if the EMF is 12V?
Solution:
Understanding these concepts is essential for mastering electrical circuits and preparing for practical applications in physics.