# Help needed on Logic Gate Questions

Discussion in 'Homework Help' started by challenger516, Mar 30, 2014.

1. ### challenger516 Thread Starter New Member

Mar 30, 2014
2
0
Hi, I am new to this forum, is it possible to help me on few Logic Gate questions please and the homework require us to name all of the gate.
Thank you

ok sorry guys, I did the first three logic gate.
First one I do not know the name of the gate.
A B X
0 0 0
1 0 1
0 1 1
1 1 0

NOR Gate
A B X
0 0 1
0 1 0
1 0 0
1 1 0

NOR gate
A B X
0 0 1
0 1 0
1 0 0
1 1 0

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Last edited: Mar 30, 2014

Jul 18, 2013
11,140
2,636
Fill in the truth table boxes and we will check it.
Max.

3. ### djsfantasi AAC Fanatic!

Apr 11, 2010
3,053
939
This is Homework Help; not homework done for you. Fill in the tables as best you can, and repost the question.

4. ### ericgibbs AAC Fanatic!

Jan 29, 2010
2,699
428
hi 516,
Its usual for homework questions to post what you think the answers are, we can give help based on your answers.

E

5. ### challenger516 Thread Starter New Member

Mar 30, 2014
2
0
ok sorry guys, I did the first three logic gate.
First one I do not know the name of the gate.
A B X
0 0 0
1 0 1
0 1 1
1 1 0

NOR Gate
A B X
0 0 1
0 1 0
1 0 0
1 1 0

NOR gate
A B X
0 0 1
0 1 0
1 0 0
1 1 0

6. ### Papabravo Expert

Feb 24, 2006
10,423
1,877
The first gate does not have an official name. I think the truth table is wrong. The output is a 1 when A=1 or B=0. In words this would be A OR NOT B. The truth table you wrote was for Exclusive OR (XOR).

7. ### shteii01 AAC Fanatic!

Feb 19, 2010
3,559
517
Papabravo likes this.
8. ### Papabravo Expert

Feb 24, 2006
10,423
1,877
Except that there is no entry for (A | ~B) which we know cannot be equivalent to (A ^ B)

Nice table -- good article BTW

9. ### WBahn Moderator

Mar 31, 2012
18,290
4,959
All of the 2-input logic gates have names, it's just that the asymmetric ones are seldom used (by name).

A implies B means that if A is True, then B is True. If A is False, then B could be either True or False, so

 A​ B​ $A \to B$​ 0[/center] 0​ 1​ 0[/center] 1​ 1​ 1[/center] 0​ 0​ 1[/center] 1​ 1​

The proper name is actually "material implication". The remaining gates have similar names and meanings.

http://en.wikipedia.org/wiki/Truth_table#Logical_implication