Logic Gate Simulator

Explore all six logic gates (AND, OR, NOT, XOR, NAND, NOR) with interactive inputs, truth tables, and compound expression building. Matches AQA A Level CS (7517) specification §4.6.4.

📖 Learn Step-by-Step

Select a gate to see its symbol, truth table, and test it with interactive inputs.

A AND B

AND gate

Output is 1 only when ALL inputs are 1.

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Truth Table

A	B	Q
0	0	0
0	1	0
1	0	0
1	1	1

Logic Gate Practice Questions

An AND gate has inputs A=1 and B=0. What is the output?

0/1 mark

Show your working:

Answer:

A NAND gate has inputs A=1 and B=1. What is the output?

0/1 mark

Show your working:

Answer:

How many rows are in a truth table for a circuit with 3 inputs?

0/1 mark

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Answer:

A circuit implements Q = NOT(A OR B). When A=0 and B=0, what is Q?

0/2 marks

Show your working:

Answer:

A XOR gate has inputs A=1 and B=1. What is the output?

0/1 mark

Show your working:

Answer:

Quick reference — logic gate summary

Gate	Symbol	Inputs	Output = 1 when…
AND	∧	2	All inputs are 1
OR	∨	2	Any input is 1
NOT	¬	1	Input is 0 (inverts)
XOR	⊕	2	Inputs are different
NAND	↑	2	NOT all inputs are 1
NOR	↓	2	All inputs are 0