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Computer Science for IGCSE & O level - Boolean Logic (Section 1)

1
Which logic gate provides the inverse of the output from an AND gate?
Answer
(B)
NAND gate
2
What is the result of the expression (A AND B) OR (NOT A AND NOT B) in the provided image?
Answer
(D)
A XNOR B
3
Which gate's output is 0 only when both of its inputs are 1?
Answer
(A)
AND gate
4
Which of the following are considered universal gates?
Answer
C
D
5
Which of the following logic gates implements the Boolean expression: Y = A ⋅ B ?
Answer
(B)
AND
6
If A = 0 and B = 1, what is the output of an XOR gate?
Answer
(B)
1
7
Which gate is often used for binary addition?
Answer
(C)
XOR
8
Which type of logic gate implements the Boolean expression A AND B?
Answer
(A)
AND gate
9
Which operation is the inverse of the OR operation?
Answer
(B)
NOR
10
What does the acronym 'RPM' stand for in the context of the engine management system example?
Answer
(A)
Revolutions Per Minute
11
In Boolean algebra, what is the meaning of A * B (or A AND B)?
Answer
(B)
A and B
12
Which of the following logic circuits represents the given Boolean expression: Y = A OR (B AND C)?
Answer
(A)
A circuit with an AND gate, whose inputs are B and C. And the output of this gate is fed in an OR gate along with A.
13
What is the result of A + 1 in Boolean algebra?
Answer
(C)
1
14
What does 'binary value' refer to in the context of logic circuits?
Answer
(A)
A value that can be either a 0 or a 1.
15
Which of the following is equivalent to (A')' ?
Answer
(A)
A
16
How many truth table rows are required for a 3-input logic gate?
Answer
(D)
8
17
Which gate produces an output of '1' if and only if both inputs are '1'?
Answer
(B)
AND
18
What does the term 'digital logic' refer to?
Answer
(B)
The use of discrete voltage levels to represent information
19
If the output is 1 for A=0, B=1, and C=0, which of the following Boolean expressions could represent the corresponding logic circuit?
Answer
(B)
(NOT A AND B) OR (NOT C)
20
In the context of logic circuits, what does 'binary' refer to?
Answer
(B)
A number system with a base of 2
21
In a logic circuit designed to monitor the output of an engine management system, the output signal will go high (1) if either the exhaust temperature exceeds 400°C AND the air pressure is greater than 10 bar OR the water temperature is greater than 100°C.
Answer
(D)
The output signal will be high if the exhaust temperature exceeds 400°C and the air pressure is greater than 10 bar or the water temperature is greater than 100°C.
22
What are the outputs of a 2 input XOR gate when inputs are '0, 0', '0, 1', '1, 0' and '1, 1' respectively?
Answer
(A)
0, 1, 1, 0
23
What is the output of a XOR gate when the inputs are both the same?
Answer
(A)
0
24
What is the effect of a NOT gate on an input signal?
Answer
(B)
It complements the input signal (inverts it).
25
Which logic gate is represented by the expression (A + B)'?
Answer
(B)
NOR
26
Given the following Boolean expression: Y = (A AND B) OR (NOT C). Which of the following logic circuits would correctly implement it?
Answer
(B)
A circuit with three inputs A, B and C, where A and B are AND'd, and C is NOT'd, and the two results are OR'd.
27
Which gate provides the logical product operation?
Answer
(A)
AND gate
28
In a digital circuit, what is the most common system for representing logic states?
Answer
(B)
Binary
29
What does the term 'intermediate' refer to when discussing truth tables and circuit design?
Answer
(B)
Results within the truth table used to develop the final output.
30
What is the output of an XOR gate if both inputs are 0?
Answer
(A)
0
31
Which gate combines the inputs to produce an output if all inputs are true?
Answer
(B)
AND
32
Which gate is equivalent to an AND gate followed by a NOT gate?
Answer
(B)
NAND gate
33
What is the output of a NOR gate with inputs A=1 and B=1?
Answer
(A)
0
34
Based on the truth table for a half-adder, if the inputs are A=1 and B=1, what are the values of the sum and carry outputs?
Answer
(C)
Sum = 0, Carry = 1
35
What is the role of an OR gate?
Answer
(C)
To output 1 when at least one input is 1.
36
Consider the engine management system scenario (Task 2). If the exhaust temperature is 400°C, air pressure is 11 bar and water velocity is 5 m/s, will the output (Y) be 1?
Answer
(A)
Yes
37
Which gate's output is high only when all the inputs are low?
Answer
(B)
NOR
38
What happens to the output of an AND gate if one of the inputs is permanently connected to '0'?
Answer
(A)
Output is always 0
39
Which of the following is the correct symbol of the NOT gate?
Answer
(B)
A triangle pointing to the right with a circle
40
What is the output of a NOT gate if the input is 1?
Answer
(A)
0
41
What is the function of the 'carry' output in a full adder circuit?
Answer
(A)
To indicate if a sum overflows.
42
Which is the logical expression for a NOR gate?
Answer
(B)
¬ (A + B)
43
Which of the following gates is known as the 'exclusive OR' gate?
Answer
(C)
XOR
44
Which logic gate is also known as an inverter?
Answer
(C)
NOT
45
If A = 0 and B = 1, then what is the output of an OR gate?
Answer
(B)
1
46
Which gate outputs a '1' only if the inputs are different?
Answer
(C)
XOR
47
Based on the examples, what are the possible outputs in the circuits shown?
Answer
(B)
0 and 1
48
Which logic gate's output is LOW only when all inputs are HIGH?
Answer
(C)
NAND
49
What is the role of an OR gate in the examples shown?
Answer
(C)
It outputs 1 if at least one input is 1.
50
What is the output of a two-input AND gate if both inputs are 0?
Answer
(A)
0