When all inputs are HIGH.
The gate is called EXNOR gate. its output is high when only one input is high. the Boolean expression for this gate for two inputs A and B is AB+A'B'
The output of the AND gate is high when both inputs are high because that is the definition of an AND gate. (Ouput is true ONLY WHEN Input A AND Input B are true.)
A NOR gate
1. NAND gate is used to invert the input A (by connecting A to both inputs). 2. NAND gate used to invert B the same way 3. Now put A' and B' into into a third NAND gate. The output will be (A'B')' which is equivalent to A+B.
An OR gate outputs a 1 when at least one of its inputs is 1. This means that if either input A or input B (or both) is high (1), the output will be high (1). If both inputs are 0, the output will be 0. Thus, the OR gate functions as a logical inclusive operator.
An inverter has a high output when the input is low, and a low output when the input is high.
An AND gate
If the output of a logic gate is 1 while all inputs are logic 0, the gate is a NOR gate. A NOR gate produces a high output (1) only when all its inputs are low (0). In contrast, other gates like AND, OR, and NAND would not produce a 1 output under these conditions.
A nor gate provides an output of 0 when any input is 1.Nor gate provides the opposite of or gate. An or gate provides a 1 or true output when any of the inputs is 1 or true. Therefore the opposite output would be provided by a nor gate.
A NOR gate is a digital logic gate that outputs true (1) only when both of its inputs are false (0), effectively functioning as an inverted OR gate. In contrast, an OR gate outputs true if at least one of its inputs is true. Therefore, while the OR gate produces a high output for any combination of high inputs, the NOR gate will only produce a high output when all inputs are low. This means the NOR gate combines the functions of an OR gate with a NOT gate.
It's a "quad, 2 input nor gate". To understand the significance of a "nor" gate, you need to understand a little about digital logic. An "or" gate takes 2 or more digital inputs and if either is "on", the output will be on. (asserted high). A "nor" gate inverts the output of the "or" gate, meaning that when either of the outputs are "on", the output will be "off" (asserted low). The two input part of the description just indicates that it only accepts two inputs. So, simply stated: If either (or both) input(s) of a quad, 2 input nor gate is (are) asserted high, the output will be low. If both inputs are off (low), the output will be high.
An AND GATE has two inputs that must both be true for the output to be true. If you have two switches in series then they must both be closed for current to flow. This is analogous to having two true signals on the input of an AND GATE.