Identifying a gate from its truth table output

Tip: Choose Save as PDF in the print dialog to download. Use A4 paper size.

Identifying a gate from its truth table output

Name:
Date:
Class:
A

Quick Questions

Shade in the A or B circle for each question.

1. A gate's output column for rows 00, 01, 10, 11 is 0001. Which gate is it?
A AND
B OR
2. A gate's output column is 0111. Which gate is it?
A XOR
B OR
3. A gate's output column is 0110. Which gate is it?
A XOR
B OR
4. A gate's output column is 1110. Which gate is it?
A NOR
B NAND
5. A gate's output column is 1000. Which gate is it?
A NOR
B NAND
B

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left columnRight column
1Output column 0001 (rows 00, 01, 10, 11) AXOR = 0110
2Output column 1110 (rows 00, 01, 10, 11) B0111 is the OR pattern. NOR is the opposite of OR, so it should be 1000.
3The output is 1 only when both inputs are 0, so the column reads 1, 0, 0, 0 C0001 is the AND pattern, not OR. OR outputs 1 whenever at least one input is 1, so it should be 0111.
4The output is 1 when the inputs are different, so the column reads 0, 1, 1, 0 DThis is a NAND gate
5OR gate output column: 0001 EThis is an AND gate
6NOR gate output column: 0111 FNOR = 1000
C

Definitions

output column
D

Fill in the Blanks

Complete each line of code by filling in the missing parts.

1.
Output column 0001 is the ___ gate
2.
NOR output for 00, 01, 10, 11: ____
3.
Rows 00 01 10 11 give X = 0110 This is the ___ gate
4.
Output 0001: only row __ gives X = 1
5.
X column for rows 00 01 10 11: 0111 Gate name: __
E

Spot the Error

Shade in the letter of the line that contains an error.

Question 1
A A B X
B 0 0 1
C 0 1 0
D 1 0 1
E 1 1 0
F Gate: NAND
Question 2
A Output column: 0111
B Row 00 gives 0
C Rows 01, 10, 11 give 1
D Gate: XOR
Question 3
A Output column: 1000
B Only row 11 gives 1
C Gate: NOR
Question 4
A Output column: 0110
B Rows 00 and 11 give 1
C Gate: XOR
Question 5
A A B X
B 0 0 0
C 0 1 1
D 1 0 0
E 1 1 1
F Gate: AND

Answer Key

Identifying a gate from its truth table output
Section A: Quick Questions
Q1
A — AND
Q2
B — OR
Q3
A — XOR
Q4
B — NAND
Q5
A — NOR
Section B: Match the Pairs
Q1
Output column 0001 (rows 00, 01, 10, 11) → This is an AND gate
Q2
Output column 1110 (rows 00, 01, 10, 11) → This is a NAND gate
Q3
The output is 1 only when both inputs are 0, so the column reads 1, 0, 0, 0 → NOR = 1000
Q4
The output is 1 when the inputs are different, so the column reads 0, 1, 1, 0 → XOR = 0110
Q5
OR gate output column: 0001 → 0001 is the AND pattern, not OR. OR outputs 1 whenever at least one input is 1, so it should be 0111.
Q6
NOR gate output column: 0111 → 0111 is the OR pattern. NOR is the opposite of OR, so it should be 1000.
Section C: Definitions
Q1
output column — Read the output column for rows 00, 01, 10, 11 to name the gate: AND 0001, OR 0111, NAND 1110, NOR 1000, XOR 0110.
Section D: Fill in the Blanks
Q1
Output column 0001 is the AND gate
Q2
NOR output for 00, 01, 10, 11: 1000
Q3
Rows 00 01 10 11 give X = 0110 This is the XOR gate
Q4
Output 0001: only row 11 gives X = 1
Q5
X column for rows 00 01 10 11: 0111 Gate name: OR
Section E: Spot the Error
Q1
C — NAND has the output column 1110, so row 01 must give 1. The line should be 0 1 1.
Q2
D — The output column 0111 is an OR gate. XOR has 0110 because row 11 gives 0. It should be Gate: OR.
Q3
B — NOR (1000) gives 1 only when both inputs are 0, which is row 00. The line should be Only row 00 gives 1.
Q4
B — XOR (0110) gives 1 only when the inputs are different, so rows 01 and 10 give 1. The line should be Rows 01 and 10 give 1.
Q5
C — AND (0001) gives 1 only for row 11, so row 01 must give 0. The line should be 0 1 0.