Technical Science - Term 3 - Week 6

An electrical circuit is a closed loop that allows current to flow from a power source to various components and back. The basic components of a circuit include a power source (like a battery), conductors (wires), and loads (like resistors or light bulbs). Understanding how these components interact is crucial for analyzing and designing circuits.

There are two primary types of circuits: series and parallel. In a series circuit, components are connected end-to-end, meaning the same current flows through all components. In contrast, a parallel circuit has components connected across common points, allowing multiple paths for current to flow. This distinction affects how voltage and current behave in each type.

Ohm's Law is a fundamental principle in electronics that relates voltage (V), current (I), and resistance (R) in a circuit. The law states that V = I × R. This means that the voltage across a conductor is directly proportional to the current flowing through it, with resistance being the constant of proportionality. Understanding this relationship is essential for circuit analysis.

Consider a series circuit with a 12V battery and two resistors of 4Ω and 6Ω. The total resistance (R_total) is R1 + R2 = 4Ω + 6Ω = 10Ω. Using Ohm's Law, the current (I) can be calculated as I = V/R_total = 12V/10Ω = 1.2A. This current flows through both resistors.

In a parallel circuit with a 12V battery and two resistors of 4Ω and 6Ω, the total resistance (R_total) can be calculated using the formula 1/R_total = 1/R1 + 1/R2. Thus, 1/R_total = 1/4 + 1/6, which simplifies to R_total = 2.4Ω. The current through each resistor can then be calculated using Ohm's Law.

Given a series circuit with a 9V battery and two resistors of 3Ω and 5Ω, calculate the total resistance and the current flowing through the circuit. First, find R_total = 3Ω + 5Ω = 8Ω. Then, use Ohm's Law: I = V/R_total = 9V/8Ω = 1.125A. Discuss the implications of this current on the components.

Students are tasked with designing a simple circuit using a 12V battery and three resistors of their choice. They must calculate the total resistance and current for both series and parallel configurations. After completing their calculations, students will present their findings to the class, explaining how the circuit functions and the role of each component.

• Volts
• Amperes
• Ohms
• Watts

Answer: Ohms

Resistance is measured in Ohms, which quantifies how much a material opposes the flow of electric current.

• It splits evenly
• It is the same throughout
• It increases at each component
• It decreases at each component

Answer: It is the same throughout

In a series circuit, the same current flows through all components, as there is only one path for the current.

• 2Ω
• 10Ω
• 24Ω
• 0.67Ω

Answer: 10Ω

In a series circuit, total resistance is the sum of individual resistances: 4Ω + 6Ω = 10Ω.

• V = I + R
• V = I × R
• V = I - R
• V = R/I

Answer: V = I × R

Ohm's Law defines the relationship between voltage, current, and resistance in an electrical circuit.

Answer: A parallel circuit is a type of electrical circuit where components are connected across common points, allowing multiple paths for current to flow.

This configuration allows for different components to operate independently, affecting the overall current and voltage in the circuit.

Answer: 2A

Using Ohm's Law, I = V/R = 10V/5Ω = 2A.

• It increases
• It decreases
• It remains the same
• It doubles

Answer: It decreases