Technical Science - Term 2 - Week 5

An electrical circuit consists of various components that work together to allow the flow of electric current. The main components include resistors, capacitors, inductors, power sources (like batteries), and conductors (wires). Resistors limit the flow of current, capacitors store electrical energy, and inductors oppose changes in current. Understanding these components is crucial for analyzing how circuits function.

Ohm's Law is a fundamental principle in electronics that relates voltage (V), current (I), and resistance (R) in a circuit. It is expressed by the formula V = I × R. This law allows us to calculate one of the three variables if the other two are known. For example, if a circuit has a voltage of 12 volts and a resistance of 4 ohms, the current can be calculated as I = V/R, which equals 3 amperes.

Consider a circuit with a voltage of 24 volts and a resistor of 6 ohms. To find the current, we use Ohm's Law: I = V/R. Substituting the values, we get I = 24V / 6Ω = 4A. This means that the current flowing through the circuit is 4 amperes.

If a circuit has a current of 2 amperes and a voltage of 10 volts, we can find the resistance using Ohm's Law rearranged as R = V/I. Plugging in the values gives us R = 10V / 2A = 5Ω. Therefore, the resistance in this circuit is 5 ohms.

Let's work through a problem together. A circuit has a resistance of 10 ohms and a current of 2 amperes. What is the voltage? Using Ohm's Law, we can find the voltage: V = I × R = 2A × 10Ω = 20V. Now, try to solve a similar problem: If the resistance is 15 ohms and the current is 3 amperes, what is the voltage?

Now it's your turn to practice independently. Solve the following problems: 1) A circuit has a voltage of 30 volts and a resistance of 5 ohms. Calculate the current. 2) If a circuit has a current of 4 amperes and a voltage of 12 volts, what is the resistance? 3) Analyze a circuit with a voltage of 50 volts and a resistance of 25 ohms. What is the current flowing through the circuit?

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

Answer: V = I × R

Ohm's Law states that voltage is equal to the current multiplied by the resistance.

• Capacitor
• Inductor
• Resistor
• Power Source

Answer: Resistor

Resistors are designed to limit the flow of electric current in a circuit.

Answer: A capacitor stores electrical energy temporarily.

Capacitors can store and release energy, making them essential for smoothing out voltage fluctuations.

• 3 A
• 4 A
• 2 A
• 1 A

Answer: 3 A

Using Ohm's Law, I = V/R = 12V / 4Ω = 3A.

Answer: Ohm

Resistance is measured in ohms, symbolized by the Greek letter omega (Ω).

• It is less than the smallest resistance.
• It is equal to the sum of individual resistances.
• It is the same as the largest resistance.
• It is zero.

Answer: It is equal to the sum of individual resistances.

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

Answer: In a series circuit, components are connected end-to-end, while in a parallel circuit, components are connected across the same voltage source.

Series circuits have the same current flowing through all components, while parallel circuits have the same voltage across all components.