Which of these sets of logic gates are known as universal gates?a.XOR, NAND, ORb.OR, NOT, XORc.NOR, NAND, XNORd.NOR, NAND

Identifying Universal Gates

1. Break Down the Problem

   • Universal gates are those that can be used to create any other type of logic gate. The two most common universal gates are NAND and NOR.

2. Relevant Concepts

   • NAND Gate: A NAND gate outputs false only when both inputs are true. It is universal because combinations of NAND gates can recreate any other logic gate.
   • NOR Gate: A NOR gate outputs true only when both inputs are false. Like NAND, NOR gates can also reproduce any other logic gate when combined properly.

3. Analysis and Detail

   • Set a: XOR, NAND, OR - This set includes XOR, which is not a universal gate. Hence, this option is invalid.
   • Set b: OR, NOT, XOR - This combination does not include any universal gates, so this option is also invalid.
   • Set c: NOR, NAND, XNOR - This includes NOR and NAND, both of which are universal gates, but XNOR is not a universal gate by itself. Thus, this option is not correct as well.
   • Set d: NOR, NAND - This option contains both NOR and NAND, which are the universal gates.

4. Verify and Summarize

   • After analyzing each set, the only set that consists solely of universal gates is option d.

Final Answer

The correct answer is d. NOR, NAND.