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Science / Electronics basics / Grade 11 / seb80

Electronics Basics: Read Logic Levels

Use ideal logic values without confusing them with universal voltages.

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For this worksheet, 0 means logical false and 1 means logical true. AND outputs 1 only when both inputs are 1. OR is inclusive: either or both inputs at 1 gives output 1. NOT flips a bit. Real voltage thresholds depend on the device and supply. Use diagrams and calculations only. Never use wall outlets, short batteries, open powered equipment or handle charged capacitors.

Worked example

For A = 1 and B = 0, AND outputs 0 and OR outputs 1. NOT B is 1. A truth table lists all four possible input pairs, not the speed of a real circuit.

An ideal truth table lists input A, input B, AND output and inclusive OR output. AND gives one only for two ones; OR gives one for either or both ones. Real voltage thresholds depend on the device.
An ideal truth table lists input A, input B, AND output and inclusive OR output. AND gives one only for two ones; OR gives one for either or both ones. Real voltage thresholds depend on the device.
Question 1 For A = 1 and B = 0, what is AND?
Question 2 For A = 1 and B = 0, what is inclusive OR?
Question 3 For A = 1 and B = 1, what is inclusive OR?
Question 4 What is NOT 0?
Question 5 Does logical 1 always mean exactly 5 V in every device?