4.5 - Logic Gates

Question 1

What is the XOR gate and what is its output? Draw it:

Answer 1

Exclusive OR gate
If one but not both of the inputs is 1 the output is 1, otherwise the output is 0
OrR gate with a line through the wires (check)

Question 2

What is the NAND gate and what is its output? Draw it:

Answer 2

Combination of AND and NOT
Inverts the output of the And gate
AND gate with a dot hen line for the output wire

Question 3

What is the NOR gate and what is its output? Draw it:

Answer 3

Inverse the OR gate
Output is 1 only if both the inputs are 0
OR gate with a dot and then a wire for the output

Question 4

What is the universal gate?

Answer 4

NAND as it combines the functions of two gates (AND, NOT) into a single gate
Different combinations of NAND can act like OR, NOT, AND gates
Any circuit can be built just by NAND

Question 5

Advantages of NAND gates?

Answer 5

Minimises cost of production if only NAND is needed
Speed up processing