Skip to main content
Ch 26: Direct-Current Circuits
Young & Freedman Calc - University Physics 15th Edition
Young & Freedman Calc15th EditionUniversity PhysicsISBN: 9780135159552Non è quello che usi tu?Cambia libro di testo
Capitolo 26, Problema 22a

The batteries shown in the circuit in Fig. E26.24 have negligibly small internal resistances. Find the current through the 30.0-Ω resistor.

Guida verificata passo dopo passo
1
Identify the components in the circuit: two batteries (E1 and E2) and two resistors (R1 and R2). The resistors are labeled with their resistance values, R1 = 30.0 Ω and R2 = unknown.
Apply Kirchhoff's loop rule to the circuit. This rule states that the sum of the electromotive forces (emf) in any closed loop is equal to the sum of the potential drops (voltage) across the resistors in that loop.
Write the equation for the loop using Kirchhoff's rule: E1 - I * R1 - E2 - I * R2 = 0, where I is the current through the resistors.
Rearrange the equation to solve for the current I: I = (E1 - E2) / (R1 + R2).
Substitute the known values into the equation. You have R1 = 30.0 Ω, and you need to know the values of E1, E2, and R2 to find the current I through the 30.0 Ω resistor.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
3m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Ohm's Law

Ohm's Law is a fundamental principle in electronics and electrical engineering, stating that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance. It is mathematically expressed as I = V/R, where I is the current, V is the voltage, and R is the resistance. This law is crucial for calculating the current in circuits.
Video consigliato:
Percorso guidato
03:07
Resistance and Ohm's Law

Kirchhoff's Loop Rule

Kirchhoff's Loop Rule, also known as Kirchhoff's Voltage Law, states that the sum of the electromotive forces (emf) and potential differences (voltage) around any closed loop in a circuit is zero. This principle is essential for analyzing complex circuits, as it allows for the calculation of unknown currents and voltages by setting up equations based on the conservation of energy within the loop.
Video consigliato:
Percorso guidato
11:15
Intro to Kirchhoff's Loop Rule

Series and Parallel Circuits

In a series circuit, components are connected end-to-end, so the same current flows through each component, and the total resistance is the sum of individual resistances. In a parallel circuit, components are connected across the same voltage source, and the total current is the sum of the currents through each component. Understanding these configurations is vital for analyzing how current and voltage distribute in a circuit.
Video consigliato:
Percorso guidato
09:51
Combining Capacitors in Series & Parallel