Technical Science - Term 2 - Week 6

An electrical circuit consists of several key components: a power source (like a battery), conductors (wires), and loads (devices that use electricity, such as bulbs or motors). The flow of electric current is driven by the voltage provided by the power source. Understanding these components is crucial for analyzing how circuits function.

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 of circuit.

Ohm's Law is a fundamental principle in electronics that relates voltage (V), current (I), and resistance (R) in a circuit. The law is expressed as V = I × R. This means that the voltage across a conductor is directly proportional to the current flowing through it, provided the temperature remains constant. Understanding this relationship is essential for calculating unknown values in electrical circuits.

Consider a series circuit with a 12V battery and two resistors of 4Ω and 6Ω. To find the total resistance (R_total), we add the resistances: R_total = 4Ω + 6Ω = 10Ω. Using Ohm's Law, we can find the current (I) flowing through the circuit: I = V/R_total = 12V/10Ω = 1.2A. Thus, the current flowing through each component is 1.2A.

In a parallel circuit with a 12V battery and two resistors of 4Ω and 6Ω, we first find the total resistance using the formula 1/R_total = 1/R1 + 1/R2. This gives us 1/R_total = 1/4 + 1/6, which simplifies to R_total = 2.4Ω. Using Ohm's Law, the total current (I_total) is I_total = V/R_total = 12V/2.4Ω = 5A. The current through each resistor can be calculated separately.

Let's work through a problem together. A series circuit has a 9V battery and two resistors of 3Ω and 5Ω. First, calculate the total resistance: R_total = 3Ω + 5Ω = 8Ω. Now, apply Ohm's Law to find the current: I = V/R_total = 9V/8Ω. What is the current flowing through the circuit?

Now, let's analyze a parallel circuit with a 12V battery and two resistors of 8Ω and 12Ω. Start by calculating the total resistance using the parallel formula. What is the total resistance, and how would you find the current flowing through each resistor?

For independent practice, solve the following problems: 1) A series circuit with a 15V battery and resistors of 5Ω and 10Ω. Calculate the total current. 2) A parallel circuit with a 24V battery and resistors of 6Ω and 3Ω. Find the total current and the current through each resistor. Show all your calculations.

Consider a household circuit with multiple appliances connected in parallel. Discuss how the principles of voltage and current apply to this scenario. What happens if one appliance fails? Write a short paragraph summarizing your thoughts.

• Volts
• Amperes
• Ohms
• Watts

Answer: Ohms

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

• The same through all components
• Different in each component
• Zero
• Variable depending on voltage

Answer: The same through all components

In a series circuit, the same current flows through each component due to the single path for current flow.

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

Answer: It decreases

Adding more resistors in parallel provides additional paths for current, which reduces the overall resistance.

Answer: V = I × R

Ohm's Law states that the voltage (V) across a conductor is equal to the product of the current (I) flowing through it and the resistance (R) of the conductor.

Answer: 2A

Using Ohm's Law, I = V/R = 20V/10Ω = 2A.

• Resistor
• Capacitor
• Inductor
• Transistor

Answer: Capacitor

A capacitor is designed to store electrical energy in an electric field.

• The same
• Different
• Zero
• Variable depending on current

Answer: The same

In a parallel circuit, each component experiences the same voltage as the source.