- Physics
- Kit
- Class 10 to 12
AND OR NOT NAND NOR Logic Gates Working Project
Code B0G2T94SJB
- Paid for and delivered by Amazon. The current price and the delivery date for your PIN code are shown there.
- Sold by Gurukul Technicals Institute, Delhi.
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In this project guide
Kit
About this kit
A working project that demonstrates five logic gates, AND, OR, NOT, NAND and NOR, so students can test each gate's truth table by changing the inputs and checking the output. It is a hands-on way to understand the yes-or-no decisions that every computer and digital device makes.
What the listing says
- CBSE Physics Investigatory Kit Educational Electronic Hobby Kit
How it works
The science behind it
The idea the kit demonstrates, in words you can use in your report and when you explain it.
Digital circuits work with only two states, 1 (high voltage) and 0 (low voltage), and logic gates combine inputs according to Boolean algebra. An AND gate (Y = A·B) gives 1 only when all inputs are 1. An OR gate (Y = A + B) gives 1 when at least one input is 1. A NOT gate inverts its single input, so 1 becomes 0. A NAND gate is an AND followed by a NOT, giving 0 only when all inputs are 1, and a NOR gate is an OR followed by a NOT, giving 1 only when all inputs are 0. NAND and NOR are called universal gates because any other gate, and therefore any digital circuit, can be built from just one of them. A bank locker that opens only when both the customer's key and the bank's key are turned works like an AND gate.
Make it yourself
Make an AND, OR, NOT, NAND and NOR gate board with logic chips yourself
Everything you need and the order to do it in. Tick off the materials as you collect them.
What you need 9
Step by step 8 steps
Fit the five sockets in a row. On each of these 14-pin chips, pin 14 goes to positive and pin 7 to negative; add a 0.1 µF capacitor across those two pins on every chip.
Wire input switches A and B so each connects its input line to positive when on, with a 10 kΩ resistor holding the line at 0 V when off. Add an input LED with its resistor on each line.
Check each chip's pin layout in its datasheet before wiring: the AND, OR and NAND chips share one layout, but on the NOR chip the output is pin 1 and the inputs are pins 2 and 3.
Run line A to one input and line B to the other input of one gate on each of the AND, OR, NAND and NOR chips, and line A alone to one inverter on the NOT chip.
Connect each gate's output through a 330 Ω resistor to its own LED, and label the LEDs AND, OR, NOT A, NAND and NOR with their symbols.
Tie every unused input on every chip to negative, since floating inputs on these chips can make them behave oddly and warm up.
Insert the chips with their notches matching the sockets, switch on, and step through 00, 01, 10 and 11, recording each output LED in a truth table.
Compare the NAND LED with the AND LED, and the NOR LED with the OR LED, for every input, to show that each pair always gives opposite outputs.
Read this first
Safety first
Go through these points before you build or switch anything on. Younger students should do this with an adult.
- Run the board on the 4.5 V cell pack only; these chips must not be connected straight to a 9 V battery.
- Use the soldering iron only with an adult, and solder the sockets, not the chips, so heat cannot harm them.
- Touch a large metal object before handling the chips, because static from your body can damage them.
- If a chip gets hot, switch off at once; it is probably in its socket the wrong way round.
Troubleshooting
If something does not work
The usual problems with this kit and how to fix them. Open a problem to see the fix.
An output LED flickers or glows when no switch is on
An input is floating. Check the 10 kΩ pull-down resistors on A and B, and tie all unused inputs to negative.
The NOR gate gives nonsense results
It was probably wired using the AND chip's layout. On the 74HC02 the output is pin 1 and the inputs are pins 2 and 3; rewire to match its datasheet.
A chip gets warm and nothing works
It is in its socket the wrong way round. Switch off, turn it so the notch matches the socket, and test again; it may need replacing.
All the LEDs are dim
The cells are weak. Measure the supply; it should be above about 4 V for clear outputs.
Exhibition day
How to present it
A running order for the exhibition table or the practical, step by step.
Go through each gate's truth table live while the judge watches, covering every input combination: four for each two-input gate and two for NOT.
Keep printed truth tables for all five gates beside the model so viewers can check each output.
Explain why NAND and NOR are universal gates, with one example such as a NOT gate made from a NAND.
Link each gate to real life, like a bank locker for AND and a doorbell with two buttons for OR.
Practice
Viva questions
Practice questions on this kit, with short answers. Try each one aloud before you open the answer.
Why are NAND and NOR called universal gates?
Any other logic gate, and so any digital circuit, can be built using only NAND gates or only NOR gates.
What is the output of a NOR gate when both inputs are 0?
The output is 1, because 0 OR 0 is 0 and the NOT of that is 1.
Write the Boolean expression for a NAND gate.
Y = (A·B)', that is, the complement of A AND B.
How many rows does the truth table of a two-input gate have?
Four, because two inputs can be 00, 01, 10 or 11, which is 2 raised to the power 2.
Project file
Project file outline
The headings of the project file, in order. Give each heading its own section and write it in your own words.
Free ebook: Writing a Science Project FileContents
- Aim: to verify the truth tables of AND, OR, NOT, NAND and NOR gates
- Introduction: digital signals and Boolean algebra
- Symbols, Boolean expressions and truth tables of the five gates
- The logic chips used, and their pin diagrams
- Circuit diagram and construction of the board
- Observations: truth tables recorded from the board
- NAND and NOR as universal gates, with diagrams
- Applications of logic gates in everyday devices
- Conclusion and bibliography
Buying checklist
Before you buy
What to check before you order the kit, and what to do when it arrives.
1Before you order
- Check which gates your syllabus and teacher want; this project covers five, so confirm whether XOR or XNOR is also needed.
- Read the listing to see how the gates are built and powered, and arrange cells or a supply if needed.
- Practise explaining why NAND and NOR are called universal gates.
- Keep the box and spare cells.
- Check the delivery date for your PIN code on the marketplace, and order well before the exhibition or practical.
- Check whether it arrives assembled. The listing calls it a kit, so look at the photos and the box contents on the marketplace before you order.
2When it arrives
- Test every gate with all four input combinations as soon as it arrives, and write the truth tables yourself.
Next steps
Take it further
Ways to turn this kit into a bigger investigation or a stronger exhibition entry.
Use only the four NAND gates on the 74HC00 to build NOT, AND and OR, and show that their truth tables match the dedicated gates.
Add an XOR chip and build a half adder that adds two one-bit numbers, with sum and carry LEDs.
Design a voting circuit for three judges in which a light shows when at least two of them vote yes.
Audience
Who it suits
Suits Class 11 and 12 physics investigatory projects and computer science students learning Boolean logic.
- ClassClass 10 to 12
- SubjectPhysics
- TypeKit
Free to read
Free ebooks for this topic
Free PDF ebooks from Gurukul Technicals Institute on the science, the making and the presenting of projects like this one.
- Free PDF ebook
Physics Working Models Explained
Twenty classic models, how each works and how to make it
- Free PDF ebook
Investigatory Projects for Class 11 and 12
Topics, method and report structure for physics, chemistry and biology
- Free PDF ebook
Your Science Exhibition Guide
Choose a project, build it, present it and answer the judges with confidence
