Logic Gates Worksheet, Computer Science Please clearly state the ... - Free Printable

Let's solve this Logic Gates Worksheet step by step.

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🔹 Step 1: Identify the Logic Gates

We are given three logic gate symbols and descriptions. Let’s label each one correctly based on their shape and description.

#### Gate 1:
- Symbol: A curved shape with two inputs and a single output (like a "D" shape).
- Description: *"This gate takes two inputs and gives an output if either one input or the other input or both inputs are true."*
- ✔ This is an OR gate.

> Label: OR gate

#### Gate 2:
- Symbol: A rounded rectangle with two inputs.
- Description: *"This gate takes two inputs and gives an output only if both inputs are true."*
- ✔ This is an AND gate.

> Label: AND gate

#### Gate 3:
- Symbol: A triangle with a small circle at the output.
- Description: *"This gate takes one input and gives an output that is the opposite value to the input."*
- ✔ This is a NOT gate (also called an inverter).

> Label: NOT gate

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🔹 Step 2: Fill in the Truth Tables

#### ✔ OR Gate Truth Table
| Input A | Input B | Output |
|---------|---------|--------|
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 1 |

> Rule: Output is 1 if at least one input is 1.

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#### ✔ AND Gate Truth Table
| Input A | Input B | Output |
|---------|---------|--------|
| 0 | 0 | 0 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |

> Rule: Output is 1 only if both inputs are 1.

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#### ✔ NOT Gate Truth Table
| Input | Output |
|-------|--------|
| 0 | 1 |
| 1 | 0 |

> Rule: Output is the inverse of the input.

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🔹 Step 3: Analyze the Combined Circuit

We have a combination of two gates:

- Input A goes into a NOT gate → output is C
- Inputs C and B go into an AND gate → final Output

So:
- C = NOT A
- Output = C AND B = (NOT A) AND B

Let’s fill in the truth table step by step.

| Input A | Input B | C (NOT A) | Output ((NOT A) AND B) |
|---------|---------|-----------|--------------------------|
| 0 | 0 | 1 | 1 AND 0 = 0 |
| 0 | 1 | 1 | 1 AND 1 = 1 |
| 1 | 0 | 0 | 0 AND 0 = 0 |
| 1 | 1 | 0 | 0 AND 1 = 0 |

✔ Final Truth Table:

| Input A | Input B | C | Output |
|---------|---------|-----|--------|
| 0 | 0 | 1 | 0 |
| 0 | 1 | 1 | 1 |
| 1 | 0 | 0 | 0 |
| 1 | 1 | 0 | 0 |

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📌 Summary

#### Labels:
1. First gate → OR gate
2. Second gate → AND gate
3. Third gate → NOT gate

#### Truth Tables:

OR Gate:
| A | B | Output |
|---|---|--------|
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 1 |

AND Gate:
| A | B | Output |
|---|---|--------|
| 0 | 0 | 0 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |

NOT Gate:
| Input | Output |
|-------|--------|
| 0 | 1 |
| 1 | 0 |

Combined Circuit (NOT then AND):
| A | B | C | Output |
|---|---|---|--------|
| 0 | 0 | 1 | 0 |
| 0 | 1 | 1 | 1 |
| 1 | 0 | 0 | 0 |
| 1 | 1 | 0 | 0 |

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This circuit is equivalent to the NAND gate but not exactly — wait, actually it's not NAND. Let's double-check:

- Output = (NOT A) AND B → This is a specific combination, often called a B AND NOT A, which is a conditional type logic.

It’s not a standard gate name like NAND or NOR, but it's a valid Boolean expression:
👉 Output = B · ¬A

So, the output is true only when B is true and A is false.

✔ That matches our table.

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✔ Final Answer:

Labels:
- First gate: OR
- Second gate: AND
- Third gate: NOT

Truth tables filled as above.

Let me know if you want a visual diagram or explanation of how to draw it!