4. Logic Gates

Question 1

What is a logic gate?

Answer 1

a logic gate is a basic foundation of a digital circuit.

Question 2

What is a digital circuit?

Answer 2

a circuit where electronic signals are one of two values: High Voltage (1) and Low Voltage (0).

Question 3

What is Voltage?

Answer 3

the potential difference across two electrical components needed to make electricity flow through it.

Question 4

What is a Microprocessor?

Answer 4

an integrated circuit that provides the same functions of a CPU.

Question 5

What is a truth table?

Answer 5

a way of showing every outcome of a logic gate.

Question 6

Name three different types of logic gates:

Answer 6

Any three of these:

1: AND gate
2: OR gate
3: NOT gate
4: NAND gate
5: NOR gate
6: XOR (EXOR) gate

Question 7

What does an AND gate look like?

Answer 7

=D-

Question 8

How are inputs processed through an AND gate?

Answer 8

When using an AND gate, the output (X) would only be high voltage (1) if both inputs (A and B) are high voltage.

Question 9

What does an OR gate look like?

Answer 9

=)D-

Question 10

How are inputs processed through an OR gate?

Answer 10

When using an OR gate the output (X) will only be high voltage (1) if the input (A) or (B) is high voltage.

Question 11

What does an NOT gate look like?

Answer 11

-▷°-

Question 12

How are inputs processed through a NOT gate?

Answer 12

When using a NOT gate, there is only one input and output. The output (X) will be high voltage only if the input is low voltage.

Question 13

What is the logic statement of an AND gate?

Answer 13

X = A and B or X = A.B

Question 14

What is the logic statement of an OR gate?

Answer 14

X = A OR b or X = A+B

Question 15

What is the logic statement of a NOT gate?

Answer 15

X = NOT A or X = A’

Question 16

How many inputs are there in a NOT gate?

Answer 16

1

Question 17

When the input of a NOT gate is 1, …

Answer 17

the output is 0.

Question 18

How are inputs processed through a NAND gate?

Answer 18

A NAND gate is a combination of an AND gate and a NOT gate. The Output will be high voltage unless both inputs are high voltage. If both inputs are high voltage the output will be low voltage. This means that X will always be 1 unless A and B are 1.

Question 19

How are inputs processed through a NOR gate?

Answer 19

A NOR gate is a combination of an OR gate and a NOT gate. The output X will be high voltage unless both inputs are high voltage. If neither inputs are high voltage, the output will be low voltage. That means that X will always be 0 unless A and B are 0.

Question 20

How are inputs processed through an XOR (EOR) gate?

Answer 20

An XOR gate (exclusive OR) has a slightly changed logic from OR gates. Similar to an OR gate, the output X will be high voltage if either of the outputs is high voltage. However in an XOR gate, if both inputs are high voltage, the output will be low voltage. That means output X will always be 1 if inputs A and B are different.

Question 21

What is the role of a logic gate in a logic circuit?

Answer 21

A logic gate controls the flow of electrical signals in a circuit.