Title: Year 12 / Computer Science / Theory / 3 - Hardware / 3.2 - Logic Gates and Logic Circuits

Q: Describe what is meant by a logic gate
A: a simple circuit made up of switches that have been combined in different ways

Q: Describe the function of a NOT gate
A: outputs the opposite of the input, so if 0 is input, it outputs 1, if 1 is input it outputs 0

Q: Describe the function of a AND gate
A: it outputs 1 if both inputs are 1, otherwise it outputs 0

Q: Describe the function of an OR gate
A: outputs 1 if either of the inputs are 1, otherwise outputs 0

Q: Describe the function of a NAND gate
A: outputs the opposite of the and gate

Q: Describe the function of a NOR gate
A: outputs the opposite of the OR gate, outputs 1 only if both inputs are 0

Q: Describe the function of a XOR gate
A: outputs 1 if only one of the inputs, but not both, are 1, otherwise it outputs 0

Q: Describe why the NAND gate is known as the universal gate
A: it combines the functions of two gates in a single gate
different combinations of nand gates can act like NOT, OR and AND gates
any circuit can be built using just NAND gates

Q: State the advantages of using NAND gates
A: using only NAND gates to build a circuit can minimise cost of production
using as few gates as possible can speed up processing

Q: State what symbol this is:
A: not

Q: State what symbol this is:
A: and

Q: State what symbol this is:
A: or

Q: State what symbol this is:
A: nand

Q: State what symbol this is:
A: nor

Q: State what symbol this is:
A: xor