Technical Science - Term 1 - Week 8

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

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 = 12V/4Ω = 3A.

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

In a series circuit with two resistors, R1 = 10Ω and R2 = 5Ω, the total resistance (R_total) is the sum of the individual resistances: R_total = R1 + R2 = 10Ω + 5Ω = 15Ω. If the circuit is powered by a 30V battery, the current can be calculated using Ohm's Law: I = V/R_total = 30V / 15Ω = 2A.

Let's analyze a parallel circuit with two resistors, R1 = 8Ω and R2 = 12Ω. The total resistance in a parallel circuit can be calculated using the formula 1/R_total = 1/R1 + 1/R2. First, we find the reciprocal of each resistor: 1/R_total = 1/8 + 1/12. Finding a common denominator, we get 1/R_total = 3/24 + 2/24 = 5/24. Thus, R_total = 24/5 = 4.8Ω. Now, if this circuit is connected to a 24V battery, calculate the total current flowing through the circuit.

Now it's your turn to solve some problems. Calculate the current flowing through a circuit with a voltage of 50V and a resistance of 10Ω. Additionally, analyze a series circuit with three resistors: R1 = 4Ω, R2 = 6Ω, and R3 = 10Ω connected to a 20V battery. Find the total resistance and 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.

• Resistor
• Capacitor
• Inductor
• Switch

Answer: Capacitor

A capacitor is designed to store electrical energy in an electric field.

Answer: 4A

Using Ohm's Law, I = V/R = 60V / 15Ω = 4A.

• The sum of individual resistances
• The product of individual resistances
• The average of individual resistances
• None of the above

Answer: The sum of individual resistances

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

Answer: 2Ω

Using the formula 1/R_total = 1/R1 + 1/R2, we find R_total = 1/(1/6 + 1/3) = 2Ω.

• It decreases
• It increases
• It remains the same
• It becomes zero

Answer: It increases

Adding more branches in a parallel circuit allows more paths for current to flow, increasing the total current.

Answer: 20V

Using Ohm's Law, V = I × R = 2A × 10Ω = 20V.