Technical Science - Term 4 - Week 2

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

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 allows us to calculate one of these values if the other two are known, making it essential for solving circuit problems.

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

To draw a simple circuit diagram, start by representing the battery with a pair of parallel lines. Connect wires using straight lines, and represent a resistor with a zigzag line. For example, a circuit with a battery connected to a resistor can be illustrated with these symbols, clearly showing the flow of current.

Let's work together on a problem. A circuit has 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. Now, try to solve a similar problem with a voltage of 30 volts and a resistance of 10 ohms.

Now it's your turn to create a circuit diagram. Design a circuit that includes a 9-volt battery, a 10-ohm resistor, and a light bulb. Label all components clearly and ensure that the connections are accurate. After completing your diagram, calculate the current flowing through the circuit using Ohm's Law.

• Volts
• Amperes
• Ohms
• Watts

Answer: Ohms

Ohms is the unit used to measure electrical resistance in a circuit.

• Resistor
• Capacitor
• Inductor
• Transistor

Answer: Capacitor

A capacitor is a component that stores electrical energy in an electric field.

Answer: V = I × R

Ohm's Law states that the voltage (V) across a conductor is equal to the current (I) flowing through it multiplied by the resistance (R).

• Increases
• Decreases
• Remains the same
• Becomes zero

Answer: Decreases

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

Answer: To limit the current flow.

Resistors are used in circuits to control the amount of current that flows, protecting other components from damage.

• ||
• ----
• Z
• ∩∩

Answer: ||

In circuit diagrams, a battery is typically represented by two parallel lines, indicating the positive and negative terminals.

Answer: 3A

Using Ohm's Law, I = V / R = 15V / 5Ω = 3A.

• To increase voltage