Elektronika Dasar 001 Resistor 01 Universitas Jember

Summary

This video explains the fundamentals of resistors in electronics, covering their structure, function, and how they control electric current. The script introduces key concepts like resistance, Ohm's Law, and the resistor color code for determining resistance values. It explores how resistors are used to limit current flow and discusses their role in series circuits, demonstrating how voltage is divided across multiple resistors. The video also provides a detailed explanation of how to calculate current and voltage using Ohm’s Law and Kirchhoff’s Voltage Law, offering practical examples to help viewers grasp these essential principles of electronics.

Takeaways

• 😀 Resistors are electronic components that oppose the flow of electrical current, also known as resistance or impedance.
• 😀 The symbol for a resistor is often depicted as a zig-zag line or a simple rectangle in circuit diagrams.
• 😀 Resistors are commonly made from carbon, with their resistance value determined by the length, material resistivity, and cross-sectional area.
• 😀 The value of a resistor can be read using color bands, with each color representing a specific digit or tolerance.
• 😀 The color code for resistors starts with black (0) and goes through colors like brown (1), red (2), orange (3), etc., to indicate resistance values.
• 😀 Tolerance of resistors is indicated by the last color band, with gold meaning 5% tolerance and silver meaning 10% tolerance.
• 😀 The formula for calculating resistance is R = ρ * l / a, where ρ is the material's resistivity, l is the length, and a is the cross-sectional area.
• 😀 Ohm's Law (V = R * I) defines the relationship between voltage (V), resistance (R), and current (I) in a circuit.
• 😀 In a series circuit, the total voltage is the sum of the individual voltages across each resistor, and the current is the same through all components.
• 😀 Kirchhoff's Voltage Law (KVL) states that the sum of all voltage differences around a closed loop is zero, helping in solving circuits with multiple resistors.
• 😀 The video includes an example problem demonstrating how to calculate current and voltage drops in a series circuit using Ohm's Law and Kirchhoff's Voltage Law.

Q & A

What is the primary function of a resistor in an electronic circuit?

A resistor's primary function is to resist the flow of electric current, creating an opposition or 'resistance' to the electrical flow in a circuit.

What does the color coding on resistors represent?

The color coding on resistors represents the resistance value and tolerance. Each color corresponds to a specific digit, and the final color often indicates the tolerance of the resistor.

What are the factors that determine the resistance of a resistor?

The resistance of a resistor is determined by the material's resistivity (e.g., carbon), the length of the resistor, and its cross-sectional area.

How is the resistance value calculated for a resistor made from carbon?

The resistance value for a resistor made from carbon is calculated using the formula: R = ρ * (l / A), where ρ is the material's resistivity, l is the length, and A is the cross-sectional area.

What is the formula for Ohm's Law, and what do the variables represent?

The formula for Ohm's Law is V = R * I, where V is the voltage (in volts), R is the resistance (in ohms), and I is the current (in amperes).

What happens in a series circuit when resistors are connected together?

In a series circuit, the total voltage is the sum of the individual voltages across each resistor, and the current remains the same throughout the circuit.

What is the total voltage in a series circuit with resistors of 9Ω, 5Ω, and 10Ω, given a supply voltage of 24V?

The total voltage across the resistors in a series circuit is equal to the supply voltage, which is 24V in this case. The individual voltage drops across each resistor can be calculated using Ohm's Law.

How do you calculate the current in a series circuit with known resistances and total voltage?

To calculate the current in a series circuit, you first calculate the total resistance by adding up the individual resistances. Then, use Ohm's Law (I = V / R_total) to find the current.

If the current in the circuit is found to be 1 ampere, how do you calculate the voltage drop across each resistor?

To calculate the voltage drop across each resistor, multiply the current by the resistance value of each resistor (V = R * I). For example, for a 9Ω resistor and a current of 1A, the voltage drop would be V = 9Ω * 1A = 9V.

What is the significance of the tolerance marking on a resistor?

The tolerance marking on a resistor indicates the allowable variation in the actual resistance value from the stated value. Common tolerances include ±5% (gold) and ±10% (silver), meaning the resistor's actual resistance can vary by that percentage.