Technical Science - Term 3 - Week 9

An electrical circuit consists of several key components: a power source (like a battery), conductors (wires), and load devices (like bulbs or motors). The power source provides the necessary voltage to push electrons through the circuit. Conductors allow the flow of electricity, while loads convert electrical energy into other forms of energy, such as light or motion.

There are two main types of circuits: 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 broken. In contrast, a parallel circuit has multiple paths for current to flow. If one path fails, current can still flow through other paths, allowing the circuit to remain operational.

Ohm's Law is a fundamental principle in electronics that relates voltage (V), current (I), and resistance (R) in a circuit. It is expressed as 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 crucial for analyzing and designing circuits.

Consider a series circuit with a 12V battery and two resistors: R1 = 4Ω and R2 = 8Ω. The total resistance (R_total) in a series circuit is the sum of individual resistances: R_total = R1 + R2 = 4Ω + 8Ω = 12Ω. Using Ohm's Law, we can find the current (I) flowing through the circuit: I = V / R_total = 12V / 12Ω = 1A.

In a parallel circuit with a 12V battery and two resistors: R1 = 6Ω and R2 = 3Ω, the voltage across each resistor is the same as the source voltage. Therefore, V_R1 = V_R2 = 12V. To find the current through each resistor, we apply Ohm's Law: I_R1 = V / R1 = 12V / 6Ω = 2A and I_R2 = V / R2 = 12V / 3Ω = 4A.

Students will work in pairs to analyze a series circuit with a 9V battery and three resistors: R1 = 2Ω, R2 = 3Ω, and R3 = 5Ω. They will calculate the total resistance, the current flowing through the circuit, and the voltage drop across each resistor. This exercise will reinforce their understanding of series circuits and Ohm's Law.

Students will design their own simple circuit using a 12V battery, a combination of resistors, and a light bulb. They must calculate the total resistance, current, and voltage drop across each component. After building their circuit, they will present their findings to the class, explaining how they applied Ohm's Law in their design.

• Volts
• Amperes
• Ohms
• Watts

Answer: Ohms

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

• It continues to work
• It becomes a parallel circuit
• The entire circuit is broken
• Only the failed component stops working

Answer: The entire circuit is broken

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

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

Answer: V = I × R

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

Answer: A parallel circuit is a type of electrical circuit where multiple components are connected across the same voltage source, allowing current to flow through multiple paths.

In a parallel circuit, if one component fails, the others can still function, as there are multiple paths for current.

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

Answer: It decreases

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

Answer: 4A

Using Ohm's Law (I = V / R), the current is calculated as I = 24V / 6Ω = 4A.