Technical Science - Term 1 - 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 primary types of circuits: series and parallel. In a series circuit, components are connected end-to-end, so the same current flows through all components. In contrast, a parallel circuit has multiple paths for current to flow, meaning that the voltage across each component is the same. Each type has its advantages and disadvantages, affecting how devices operate.

Ohm's Law is a fundamental principle in electronics that relates voltage (V), current (I), and resistance (R). It is expressed as V = I × R. This law allows us to calculate one of these values if the other two are known, making it 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 total 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 can be calculated using the formula 1/R_total = 1/R1 + 1/R2. Thus, 1/R_total = 1/4 + 1/6 = 5/12, leading to R_total = 12/5 = 2.4Ω. The total current can then be calculated as I = V / R_total = 12V / 2.4Ω = 5A.

Let's work together on a problem. A series circuit has a 9V battery and two resistors of 3Ω and 3Ω. First, calculate the total resistance: R_total = R1 + R2 = 3Ω + 3Ω = 6Ω. Now, apply Ohm's Law to find the current: I = V / R_total = 9V / 6Ω. What is the current flowing through the circuit?

Now, consider a parallel circuit with a 12V battery and two resistors of 8Ω and 4Ω. Calculate the total resistance using the formula 1/R_total = 1/R1 + 1/R2. After finding R_total, determine the total current supplied by the battery. Discuss your findings with a partner.

Complete the following problems independently. 1) A series circuit has a 15V battery and three resistors of 2Ω, 3Ω, and 5Ω. Calculate the total current. 2) A parallel circuit has a 24V battery and two resistors of 12Ω and 6Ω. Find the total current. Show all your calculations and reasoning.

Design a simple circuit diagram using at least one battery, two resistors, and a light bulb. Label all components and indicate whether it is a series or parallel circuit. Write a brief explanation of how you would calculate the current flowing through your circuit.

• 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
• Only in the battery

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.

• It increases
• It decreases
• It stays the same
• It becomes infinite

Answer: It decreases

Adding more resistors in parallel provides additional paths for current, which decreases the total 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.

• 2A
• 5A
• 10A
• 50A

Answer: 2A

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

Answer: 10Ω

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

• Battery
• Resistor
• Transistor
• Water Pipe

Answer: Water Pipe

A water pipe is not an electrical component; it is used in plumbing, while the others are essential in electrical circuits.