Q1: Which of the following equations would accurately describe a four-input OR gate when A = 1, B = 1, C = 0, and D = 0?

ANS:B - 1 + 1 + 0 + 0 = 1

A+B=A OR B.
AB= A AND B.

1 = TRUE
0 = FALSE.

1+1+0+0.

= TRUE OR TRUE OR FALSE OR FALSE.
= TRUE.

(IF ONLY ONE OF ALL INPUTS FOR THE 'OR' OPERATOR OR GATE IS TRUE, THEN THE RESULT IS TRUE).

THUS, 1+1+0+0=TRUE=1.

NOW,
00 = FALSE AND FALSE = FALSE,
01 = FALSE AND TRUE = FALSE.

(RESULT FOR AN 'AND' OPERATOR OR GATE IS TRUE ONLY IF ALL ITS INPUTS ARE TRUE)
THEREFORE, 1+1+0+0=1.