Technical Science - Term 3 - Week 7

An electrical circuit is a closed loop that allows electric current to flow. The basic components of a circuit include a power source (like a battery), conductors (wires), and loads (devices that use electricity, such as bulbs or motors). Understanding how these components interact is crucial for analyzing and designing circuits.

There are two main 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 multiple paths for current to flow, allowing components to operate independently. This distinction affects how voltage and current are distributed in the circuit.

Ohm's Law is a fundamental principle in electronics that states the relationship between voltage (V), current (I), and resistance (R) in a circuit. It can be expressed with the formula V = I × R. This law helps us calculate how much current will flow through a circuit given a certain voltage and resistance.

Consider a series circuit with a 12V battery and two resistors, R1 = 4Ω and R2 = 2Ω. The total resistance (R_total) is R1 + R2 = 4Ω + 2Ω = 6Ω. Using Ohm's Law, we can find the current (I) flowing through the circuit: I = V / R_total = 12V / 6Ω = 2A. Therefore, the current flowing through the circuit is 2A.

In a parallel circuit with a 12V battery and two resistors, R1 = 4Ω and R2 = 6Ω, the total resistance can be calculated 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. The current through the circuit can then be calculated as I = V / R_total = 12V / 2.4Ω = 5A.

Let's practice calculating current in a series circuit. You have a 9V battery connected to two resistors: R1 = 3Ω and R2 = 3Ω. First, find the total resistance: R_total = R1 + R2 = 3Ω + 3Ω = 6Ω. Now, use Ohm's Law to find the current: I = V / R_total. What is the current flowing through the circuit?

Now, consider a parallel circuit with a 12V battery and two resistors: R1 = 6Ω and R2 = 3Ω. Calculate the total resistance using the parallel formula. Then, determine the current flowing through each resistor. How does the voltage across each resistor compare?

For your independent practice, create a simple circuit diagram that includes a battery, two resistors in series, and a light bulb. Label all components and calculate the total resistance, current, and voltage across each component. Write a brief explanation of how changing one resistor would affect the overall circuit.

Research a real-world application of electrical circuits, such as in household wiring or electronic devices. Write a short report explaining how circuits are used in that application, including the types of circuits involved and their importance.

• 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 for each component
• Zero
• Only flows through the first component

Answer: The same through all components

In a series circuit, the same current flows through each component because there is only one path for the current to take.

• Components share the same current
• Components have multiple paths for current
• Only one component can be connected
• Current is divided equally among components

Answer: Components have multiple paths for current

A parallel circuit allows current to flow through multiple paths, meaning each component can operate independently.

Answer: V = I × R

Ohm's Law states that voltage (V) is equal to the current (I) multiplied by the resistance (R).

Answer: The total resistance increases.

In a series circuit, adding more resistors increases the total resistance because the resistances add together.

• It doubles
• It halves
• It stays the same
• It quadruples

Answer: It doubles

According to Ohm's Law, if voltage increases while resistance remains constant, the current will also increase proportionally.

Answer: In series circuits, components are connected end-to-end, sharing the same current. In parallel circuits, components are connected across common points, allowing multiple paths for current.