Technical Science - Term 3 - Week 4

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

Ohm's Law is a fundamental principle used in electrical engineering, defined by the equation V = I × R, where V is voltage, I is current, and R is resistance. This law allows us to calculate the relationship between these three variables in a circuit. For example, if we know the voltage and resistance, we can easily find the current flowing through the circuit.

Circuit diagrams use standardized symbols to represent different components in a circuit. For instance, a battery is represented by a pair of parallel lines, while a resistor is shown as a zigzag line. Learning to read and create these diagrams is essential for visualizing how circuits function.

Consider a circuit with a voltage of 12 volts and a resistance of 4 ohms. To find the current, we apply Ohm's Law: I = V / R. Substituting the values, we get I = 12V / 4Ω = 3A. This means that 3 amperes of current flow through the circuit.

Let's draw a circuit that includes a battery, a switch, and a light bulb. Start by drawing the battery symbol, then connect a line to the switch symbol. From the switch, draw a line to the light bulb symbol, and finally connect back to the battery. This diagram represents a simple series circuit where the switch controls the flow of electricity to the light bulb.

Now, let's work together on a problem. Suppose we have a circuit with a voltage of 24 volts and a resistance of 6 ohms. Using Ohm's Law, calculate the current. First, recall the formula I = V / R. Substituting the values, we find I = 24V / 6Ω = 4A. Discuss with your partner how you arrived at this answer.

In pairs, create a circuit diagram for a circuit that includes a battery, two resistors in series, and a switch. Use the correct symbols and ensure that the connections are clear. Once completed, share your diagrams with another pair and explain your design choices.

Individually, solve the following problems: 1) A circuit has a voltage of 30 volts and a resistance of 10 ohms. Calculate the current. 2) Draw a circuit diagram for a battery connected to three resistors in parallel. Label all components clearly. Submit your answers for review.

Choose 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 any relevant calculations using Ohm's Law. Be prepared to present your findings to the class.

• Volts
• Amperes
• Ohms
• Watts

Answer: Ohms

Resistance is measured in ohms, which quantifies how much a component resists the flow of electric current.

• Resistor
• Capacitor
• Inductor
• Transistor

Answer: Capacitor

A capacitor stores electrical energy in an electric field and can release it when needed.

Answer: V = I × R

Ohm's Law relates voltage (V), current (I), and resistance (R) in an electrical circuit.

• Increases
• Decreases
• Remains the same
• Becomes zero

Answer: Decreases

According to Ohm's Law, if resistance increases while voltage is constant, the current must decrease.

Answer: To control the flow of current.

A switch opens or closes a circuit, allowing or stopping the flow of current.

• It is less than the smallest resistance
• It is equal to the smallest resistance
• It is the sum of all resistances
• It is the average of all resistances

Answer: It is the sum of all resistances

In a series circuit, the total resistance is the sum of all individual resistances.

Answer: A closed circuit is a complete path for current to flow.

In a closed circuit, all components are connected, allowing electricity to flow uninterrupted.