Logic Gates – Worksheet

Task 1
Use the symbols in this table to complete your diagrams.

And Or Not NAND NOR

A P
P
B

Problem Solution Screenshot from Logic Lab

P = A OR B

P = NOT A

P = NOT (A AND B)

P = (A AND B) OR C

P = NOT (A AND B) AND C

P = ((NOT A) OR B) AND C
P = NOT ((NOT A) AND B)

P = (A OR B) AND (C OR D)

P = NOT ((A OR B) AND C)

P = A OR B OR C OR D

P = (A AND B) AND NOT C

AND OR NOT
A A
Q Q A Q
B B

RULE: Q = 1 if A AND B =1 RULE: Q = 1 if A OR B =1 RULE: Q = 0 if A =1

A Q
0
1
 NAND NOR XOR
A
A A
Q
Q Q
B
B B

RULE: Q = 0 if A AND B =1 RULE: Q = 0 if A OR B =1 Q = 1 if A OR B =1, but NOT both

A B Q A B Q
0 0 0 0
0 1 0 1
1 0 1 0 Check Your
Answers
1 1 1 1

Check Your Answers

Truth Tables

X Y
1. A Logic circuit has two inputs being X and Y
fill in all the possible combinations.

2. Find the output for the following:

b.
1

c. 1

d.
1

0
3. The figure below shows a logic circuit and its incomplete truth table. Complete the below
truth table.

A B C Q

A 0 0
C Q
B 0 1

1 0

1 1

4. The figure below shows a logic circuit and its incomplete truth table. Complete its truth table.

A C A B C D Q
Q 0 0
B

D 0 1

1 0

1 1

5. The figure below shows a logic circuit and its incomplete truth table. Complete the below
truth table.
A A B C D Q
C
Q 0

B D
1

1
6. The figure below shows a logic circuit and its incomplete truth table. Complete the below
truth table.

A
C
Q A B C D Q

0
B
D
1

7. For the logic circuit below complete the truth table.

A 0 0
D
0 1
B
1 0

1 1