# Help needed on Logic Gate Questions

#### challenger516

Joined Mar 30, 2014
2
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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Joined Jul 18, 2013
27,619
Fill in the truth table boxes and we will check it.
Max.

#### djsfantasi

Joined Apr 11, 2010
9,079
This is Homework Help; not homework done for you. Fill in the tables as best you can, and repost the question.

#### ericgibbs

Joined Jan 29, 2010
17,993
hi 516,
Its usual for homework questions to post what you think the answers are, we can give help based on your answers.

E

#### challenger516

Joined Mar 30, 2014
2
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

#### Papabravo

Joined Feb 24, 2006
20,383
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).

#### Papabravo

Joined Feb 24, 2006
20,383

#### WBahn

Joined Mar 31, 2012
29,154
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​
|
0​
|
1
0​
|
1​
|
1
1​
|
0​
|
0
1​
|
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