An AND gate can be prepared by repetitive use of

Options

A. NOT gate
B. OR gate
C. NAND gate
D. NOR gate

Answer

To determine how an AND gate can be prepared using repetitive use of other logic gates, we can analyze the options provided. The options are NOT gate, OR gate, NAND gate, and NOR gate.

### Step-by-Step Solution:

1. **Understanding Logic Gates**:
- An AND gate outputs true (1) only when both of its inputs are true (1).
- A NOT gate inverts the input (0 becomes 1 and 1 becomes 0).
- An OR gate outputs true if at least one input is true.
- NAND gate outputs false only when both inputs are true (it is the inverse of AND).
- NOR gate outputs true only when both inputs are false (it is the inverse of OR).

2. **Identifying Universal Gates**:
- NAND and NOR gates are considered universal gates. This means they can be used to create any other type of logic gate, including AND, OR, and NOT gates.

3. **Constructing an AND Gate using NAND Gates**:
- To create an AND gate using NAND gates, we can use the following configuration:
- Connect the two inputs A and B to a NAND gate. The output will be \( \overline{A \cdot B} \) (which is NOT of A AND B).
- Then, take the output of this NAND gate and connect it to another NAND gate with both inputs being the output of the first NAND gate. This will give us \( \overline{\overline{A \cdot B}} \), which simplifies to \( A \cdot B \) (the output of an AND gate).

4. **Constructing an AND Gate using NOR Gates**:
- To create an AND gate using NOR gates, we can use the following configuration:
- Connect inputs A and B to two separate NOR gates.
- The outputs of these NOR gates will be \( \overline{A} \) and \( \overline{B} \).
- Connect the outputs of these two NOR gates to a third NOR gate. The output will be \( \overline{\overline{A} + \overline{B}} \), which simplifies to \( A \cdot B \) (the output of an AND gate).

5. **Conclusion**:
- From the above analysis, we can conclude that an AND gate can be constructed using repetitive use of NAND gates or NOR gates. Therefore, the correct options are NAND gate and NOR gate.

### Final Answer:
The AND gate can be prepared by repetitive use of **NAND gate** and **NOR gate**.

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