Question

1. How are a buffer and a NOT gate similar?

2. How are a buffer and a NOT gate different?

3. When interfacing an Arduino output to a higher voltage, explain how a buffer could be used.

4. What diagram do we use to code the AND function?

5. What diagram do we use to code the OR function?

6. Draw the international diagram for an AND gate.

7. Draw the international diagram for an OR gate.

8. Draw, the truth table for a 3 input AND gate, including the output.

9. Draw the truth table for a 3 input OR gate, including the output.

10. When does 1 + 1 = 1?

Answer 1

1. How are a buffer and a NOT gate similar?

Both buffer and NOT gates has single input and single ouput.

2. How are a buffer and a NOT gate different?

The behavior that is the opposite of an NOT gate. It simply passes its input, unchanged, to its output. So, in a buffer, if the input is 1 the output will be 1 and if the input is 0 the output will be 0. In a real-world circuit, a buffer can be used to amplify a signal if its current is too weak. In contrast, for a NOT gate, if the input is 1 then the output will be 0 whereas, if the input is 0 the output will be 1. The digital Not Gate commonly called an inverter.

3. When interfacing an Arduino output to a higher voltage, explain how a buffer could be used ?

When a HIGH voltage is applied from arduino, it will create a high impedance in the logic gate buffer. So the output voltage will appear across the pull up resistor and load. So output current will flow through the pull up resistor to load. That is output will be HIGH, if the input is HIGH. Here load is an LED. This current will not enter the logic gate buffer because of high impedance of logic gate buffer.  When a LOW voltage is applied, it will create a low impedance in the logic gate buffer. So the load current will flow through the logic gate buffer and pull up resistor to ground. So voltage across the load will be LOW. That is output will be LOW, if the input is LOW.

4. What diagram do we use to code the AND function ?

5. What diagram do we use to code the OR function?

6. Draw the international diagram for an AND gate.

7. Draw the international diagram for an OR gate.

8. Draw, the truth table for a 3 input AND gate, including the output.

C	B	A	Q
0	0	0	0
0	0	1	0
0	1	0	0
0	1	1	0
1	0	0	0
1	0	1	0
1	1	0	0
1	1	1	1

9. Draw the truth table for a 3 input OR gate, including the output.

C	B	A	Q
0	0	0	0
0	0	1	1
0	1	0	1
0	1	1	1
1	0	0	1
1	0	1	1
1	1	0	1
1	1	1	1

10. When does 1 + 1 = 1?

For, an OR gate if both input value is 1 then output value will be 1. The above statement is applicable for an OR gate.