A denser practical sheet covering resistor combinations, divider outputs, LED resistor selection, voltage drop, and cable resistance in one workflow-oriented pack.
This sheet is built for the moment after basic Ohm's Law is understood and the circuit question becomes practical: combined resistors, divider outputs, LED current limiting, or cable losses.
Two 100 ohm resistors in series give 200 ohms. The same pair in parallel gives 50 ohms. A 12 V divider built from 1 kOhm over 2 kOhm gives about 8 V at the lower node. Those checks cover a large share of simple bench reasoning.
Use this sheet during breadboarding, quick worksheet checks, or design reviews where several simple circuit relationships need to stay visible on one page.
Add resistor values in series to find the total equivalent resistance for a simple chain of components.
Combine resistor values in parallel to find the equivalent resistance seen across the network.
Use the Resistor Divider Calculator for practical circuit and electronics work involving resistor divider.
Use the LED Resistor Calculator for practical circuit and electronics work involving led resistor.
Calculate the voltage dropped across a resistance from the current and resistance values you enter.
Estimate the resistance of a copper or aluminium conductor from its length and cross-sectional area.
A fuller printable revision guide for voltage, current, resistance, power, and conductance with unit discipline, worked examples, and quick bench-side checks.
A practical field guide for low-voltage cable runs, voltage drop, line resistance, and quick sizing checks, designed for installation and bench planning rather than classroom-only use.
A flagship guide to voltage, current, resistance, power, and conductance that treats Ohm's Law as a practical circuit language rather than a memorised triangle. Use it for study, design checks, fault-finding, and component-stress decisions.
A guide to resistor combinations and divider behaviour, focused on how series values add, parallel values reduce, and divider outputs depend on the ratio between resistors.
A practical guide to voltage drop, wire resistance, cable sizing decisions, and the point where the wiring stops being an invisible connection and becomes part of the circuit you have to design around.