Computer Science for IGCSE & O level - Boolean Logic (Section 2)
1
Which logic gate will produce a high output if and only if all inputs are low?
Απάντηση
(D)
NOR
2
What are the inputs to a half-adder circuit?
Απάντηση
(A)
Two binary digits
3
How many inputs does a two-input AND gate have?
Απάντηση
(B)
Two
4
In a logic gate, what does a 'high' signal typically represent?
Απάντηση
(B)
1
5
What is the simplified form of (A + 0) in Boolean algebra?
Απάντηση
(A)
A
6
What is the purpose of a carry bit in binary addition?
Απάντηση
(A)
To indicate that an addition resulted in a sum greater than 1
7
Which of the following Boolean expressions does the logic diagram represents?
Απάντηση
(A)
((NOT A) AND B) OR C
8
What is the sum and carry-out of a half-adder if the inputs are A=0 and B=1?
Απάντηση
(B)
Sum=1, Carry=0
9
In the context of the examples, what is the primary benefit of using a truth table to verify a logic circuit?
Απάντηση
(B)
It ensures that the circuit matches the logic statement.
10
In a logic circuit, the output is high (1) if motor speed is > 3000 rpm AND bearing temperature is <= 80°C, OR water velocity is > 4 m/s. Which of the following statements correctly describes the logic?
Απάντηση
(C)
The system outputs 1 if both motor speed and bearing temperature meet the conditions, or water velocity meets the condition.
11
Which of the following is equivalent to the Boolean expression NOT (A OR B)?
Απάντηση
(A)
NOT A AND NOT B
12
In Boolean algebra, what does the '.' symbol represent?
Απάντηση
(B)
AND
13
Which of the following gates is the result of inverting the output of an OR gate?
Απάντηση
(C)
NOR gate
14
Which gate is the inverse of an OR gate?
Απάντηση
(C)
NOR gate
15
What is the purpose of a circuit diagram?
Απάντηση
(C)
To graphically illustrate the components and their connections.
16
If the output of a logic gate is 0 only when all inputs are 1, what type of gate is it?
Απάντηση
(B)
NOR
17
What would be the next step after writing down a logic expression from a truth table?
Απάντηση
(A)
To create a logic circuit based on the logic expression.
18
In the context of Boolean algebra, what does '1' typically represent?
Απάντηση
(C)
True
19
Which logic gate's output is the inverse of the output of an AND gate?
Απάντηση
(B)
NAND gate
20
If a logic circuit's output is high (1) only when all input conditions are met, which type of gate is it?
Απάντηση
(B)
AND gate
21
What is the output of a NOT gate if the input is 1?
Απάντηση
(A)
0
22
What is the complement of the Boolean expression A.B?
Απάντηση
(A)
A' + B'
23
What is the output of a 2-input AND gate if the inputs are 1 and 1?
Απάντηση
(B)
1
24
What is the term for a number system based on two digits (0 and 1)?
Απάντηση
(C)
Binary
25
What is the result of the expression NOT (A AND B) when A=1 and B=0?
Απάντηση
(B)
1
26
How many inputs and outputs does a full adder have?
Απάντηση
(C)
3 inputs, 2 outputs
27
In digital circuits, what does the term 'high' often represent?
Απάντηση
(B)
1
28
What is the output of an OR gate if both inputs A and B are 1?
Απάντηση
(B)
1
29
How are the three parameters related in the wood system example?
Απάντηση
(D)
The result depends on which combination of the parameters satisfies a specific condition.
30
Which of the following statements about a NOR gate is correct?
Απάντηση
(B)
The output is HIGH if both inputs are LOW
31
In the context of logic circuits, what is a 'high' signal typically represented by?
Απάντηση
(C)
A binary 1
32
If all input conditions are not met, what will be the output value in many of the scenarios described?
Απάντηση
(A)
0
33
How does the number of possible output states increase with each additional input in a logic gate?
Απάντηση
(A)
It doubles
34
Which gate yields an output of 0 if *any* of its inputs are 1?
Απάντηση
(D)
NOR
35
In the expression Y = (A AND B) OR C, which operation is performed LAST?
Απάντηση
(B)
OR
36
What is the result of the Boolean expression 0 + 1?
Απάντηση
(B)
1
37
Which of the following is the Boolean expression for a NAND gate?
Απάντηση
(D)
(A . B)'
38
What does the term 'logic' refer to in the context of logic circuits?
Απάντηση
(B)
The mathematical principles that govern the circuit's behavior.
39
Which of the following is the correct Boolean expression for a 2-input NOR gate?
Απάντηση
(D)
NOT (A OR B)
40
What is the function of the logic gates?
Απάντηση
(C)
To process binary data
41
What is the role of sensors in the logic circuit (exam-style)?
Απάντηση
(B)
To convert real-world conditions into electrical signals for the input.
42
What is used to verify the correctness of the logic circuit?
Απάντηση
(B)
The truth table.
43
What is the function of a 'full adder' circuit?
Απάντηση
(A)
To add two single-bit binary numbers and a carry-in.
44
What is the most simplified form of the boolean expression: A + A'B?
Απάντηση
(A)
A
45
The output of an AND gate is 0 if:
Απάντηση
A
B
46
A certain logic gate always gives the output 1 if the inputs are different. Which gate is this?
Απάντηση
(B)
XOR gate
47
What is an appropriate approach for the design of a circuit?
Απάντηση
(A)
Start with a truth table, then create a logic expression, then draw the circuit.
48
In the logic circuit examples, what is the primary purpose of using a truth table?
Απάντηση
(D)
To determine the output values for all possible input combinations.
49
What is the output of a NOT gate if the input is 0?
Απάντηση
(B)
1
50
What is a truth table mainly designed to show in the examples?
Απάντηση
(B)
All possible outputs of a logic circuit for every input combination.
