Which type of gate produces an output of 1 only when exactly one of its inputs is 1? • a. NAND • b. AND • c. OR • d. XOR
The correct answer and explanation is:
The correct answer is d. XOR (Exclusive OR).
Explanation:
An XOR (Exclusive OR) gate is a digital logic gate that outputs a 1 only when the number of 1s in the inputs is odd. In simpler terms, it produces a 1 if exactly one of its inputs is 1, and 0 otherwise. Therefore, for two input variables, the XOR gate gives the following truth table:
| Input A | Input B | XOR Output |
|---|---|---|
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 0 |
As shown in the table, the XOR gate outputs a 1 only when one of the inputs is 1. If both inputs are 0 or both are 1, the output is 0. This makes XOR different from other basic gates like AND, OR, and NAND.
- AND Gate: The AND gate outputs 1 only when both inputs are 1. For any other combination, it outputs 0.
- OR Gate: The OR gate outputs 1 if at least one of its inputs is 1. It only outputs 0 when both inputs are 0.
- NAND Gate: The NAND gate is the negation of the AND gate. It outputs 1 except when both inputs are 1.
Thus, the XOR gate is the only gate among the options provided that outputs a 1 when exactly one of its inputs is 1. This feature makes it useful in various applications, such as arithmetic operations, error detection and correction, and in circuits where the behavior of two inputs needs to be mutually exclusive.