Technical Science - Term 3 - Week 1

Electrical circuits consist of several key components: resistors, capacitors, inductors, power sources, and conductors. Resistors limit the flow of electric current, capacitors store electrical energy, and inductors oppose changes in current. Power sources, such as batteries or generators, provide the necessary voltage to drive current through the circuit. Conductors, typically made of copper or aluminum, allow the flow of electricity between components.

Circuits can be classified into two main types: series and parallel. In a series circuit, components are connected end-to-end, so the same current flows through all components. If one component fails, the entire circuit is interrupted. In contrast, a parallel circuit has multiple paths for current to flow. If one path is broken, current can still flow through other paths, allowing the circuit to remain functional.

Ohm's Law is a fundamental principle in electrical engineering that relates voltage (V), current (I), and resistance (R) in a circuit. It is expressed as V = I × R. This law allows us to calculate one of these variables if the other two are known. Understanding Ohm's Law is crucial for analyzing and designing electrical circuits.

Consider a series circuit with a 12V battery and two resistors, R1 = 4Ω and R2 = 6Ω. The total resistance in the circuit is R_total = R1 + R2 = 4Ω + 6Ω = 10Ω. Using Ohm's Law, the current flowing through the circuit 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, R1 = 4Ω and R2 = 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 current through the circuit can be found using Ohm's Law: I_total = V / R_total = 12V / 2.4Ω = 5A.

Let's work together on a problem. We have a series circuit with a 9V battery and two resistors, R1 = 3Ω and R2 = 3Ω. First, calculate the total resistance: R_total = R1 + R2. Next, use Ohm's Law to find the current flowing through the circuit. What is the current?

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. Discuss your findings with a partner.

Complete the following problems independently: 1) A series circuit with a 15V battery and two resistors, R1 = 5Ω and R2 = 10Ω. Calculate the total resistance and current. 2) A parallel circuit with a 24V battery and resistors R1 = 8Ω and R2 = 4Ω. Find the total resistance and the current through each resistor. Show all your calculations.

• Ohm
• Volt
• Ampere
• Watt

Answer: Ohm

Resistance is measured in Ohms, which is the standard unit in electrical engineering.

• Only that component stops working
• The entire circuit is interrupted
• The current increases
• The voltage decreases

Answer: The entire circuit is interrupted

In a series circuit, all components are connected in a single path, so if one fails, the current cannot flow.

Answer: V = I × R

Ohm's Law states that voltage equals current multiplied by resistance.

• 2.4Ω
• 10Ω
• 24Ω
• 0.67Ω

Answer: 2.4Ω

The total resistance in a parallel circuit is calculated using the formula 1/R_total = 1/R1 + 1/R2.

Answer: The total current increases.

Adding more branches in a parallel circuit provides additional paths for current, increasing the total current.

• Resistor
• Capacitor
• Inductor
• Battery

Answer: Capacitor

Capacitors are designed to store electrical energy for later use.

• It doubles
• It halves
• It remains the same
• It quadruples

Answer: It doubles

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