Computer Science for IGCSE & O level - Boolean Logic (Section 11)
1
In the context of binary addition, what does the 'carry' bit represent?
Trả lời
(B)
The amount to be carried over to the next most significant bit column.
2
If you have an OR gate, and you want the output to be 0, what must the inputs be?
Trả lời
(C)
Both 0
3
Which gate is the inverse of an OR gate?
Trả lời
(B)
NOR
4
In a digital circuit, a NAND gate can be formed by combining an AND gate and a:
Trả lời
(A)
NOT gate
5
In the half adder circuit, the output is a carry if both inputs are:
Trả lời
(B)
1
6
Which of the following is true about logic gates?
Trả lời
(B)
They are made up of thousands of transistors
7
Which of these is not a common logic gate?
Trả lời
(D)
NOR
8
What logic gate produces an output of 1 only if its inputs are different?
Trả lời
(C)
XOR
9
Which of the following logic gates produces a 1 output if and only if all its inputs are 0?
Trả lời
(C)
NOR
10
When both inputs to a NAND gate are HIGH, the output is:
Trả lời
(B)
LOW
11
What is the simplified form of the expression A OR (A AND B)?
Trả lời
(A)
A
12
Which logic gate produces an output that is the inverse of the OR gate's output?
Trả lời
(B)
NOR gate
13
What is the fundamental function of a logic gate in digital circuits?
Trả lời
(B)
To perform logical operations.
14
The NAND gate is equivalent to an AND gate followed by what logic gate?
Trả lời
(C)
NOT gate
15
Which of the following statements describes an XOR gate?
Trả lời
(C)
Outputs HIGH if and only if inputs are different
16
A NOR gate can be made using which combination of gates?
Trả lời
(B)
OR and NOT
17
Which is the equivalent expression for NOT (A AND B)?
Trả lời
(B)
NOT A OR NOT B
18
What does the term 'binary value' represent?
Trả lời
(B)
A number in base 2
19
What is the carry output in a half adder if A=1 and B=0?
Trả lời
(A)
0
20
In a half adder circuit, what does 'sum' represent?
Trả lời
(A)
The result of adding two input bits without considering the carry.
21
The output of a NAND gate is LOW only when:
Trả lời
(C)
All inputs are HIGH
22
What is the output of a NAND gate if both inputs are 1?
Trả lời
(A)
0
23
What is the output of an XNOR gate when the inputs are 1 and 1?
Trả lời
(B)
1
24
What is the result of the Boolean expression A + A?
Trả lời
(C)
A
25
What does a Karnaugh map (K-map) help to simplify?
Trả lời
(A)
Logic circuits
26
Which logic gate is the complement of an OR gate?
Trả lời
(B)
NOR
27
A logic gate's function can be completely described by:
Trả lời
(B)
A truth table
28
In a series of logic operations represented by a truth table, what defines an input?
Trả lời
(A)
Independent variables that affect output.
29
If A = 1, what is the result of NOT A?
Trả lời
(A)
0
30
If the inputs to a 2-input AND gate are A=0 and B=0, what is the output?
Trả lời
(A)
0
31
Which of the following is equivalent to the logic expression NOT(A AND B)?
Trả lời
(C)
NOT A OR NOT B
32
What does the 'sum' output represent in a half adder?
Trả lời
(B)
The result of the binary addition
33
What type of gate results from inverting the output of a NAND gate?
Trả lời
(B)
OR
34
What is the output of a 2-input XOR gate if the inputs are A=1 and B=0?
Trả lời
(B)
1
35
How many logic gates are used to build a half adder circuit?
Trả lời
(C)
3
36
Which of the following is the simplified Boolean expression for a NAND gate with inputs A and B?
Trả lời
(C)
(A . B)'
37
What is the output of a 2-input AND gate when A=1 and B=0?
Trả lời
(A)
0
38
Which logic gate has an output of 1 only when both inputs are 1?
Trả lời
(B)
AND gate
39
If the inputs of an AND gate are A = 1 and B = 0, what will be the output?
Trả lời
(A)
0
40
Which type of gate can be described as an 'inverter'?
Trả lời
(C)
NOT gate
41
What type of logic gate is described by the expression NOT(A OR B)?
Trả lời
(C)
NOR gate
42
Which of the following Boolean expressions is equivalent to a NAND gate?
Trả lời
(D)
(A * B)'
43
Which gate outputs a HIGH (1) unless both inputs are HIGH (1)?
Trả lời
(A)
NAND
44
Which of the following gates is the most suitable for the application of a 'voting' system, where the output should be HIGH if a majority of inputs are HIGH?
Trả lời
(B)
OR
45
What is the purpose of a decoder in digital circuits?
Trả lời
(C)
To select one of several output lines based on the input.
46
Which one is a key advantage of using logic gates in computers?
Trả lời
(C)
They are very reliable.
47
What is the purpose of the NOT gate in digital circuits?
Trả lời
(B)
To invert the signal.
48
How many input combinations exist for a logic gate with two inputs?
Trả lời
(C)
4
49
A truth table is a table that shows the output of a logic gate for every possible combination of:
Trả lời
(B)
Inputs and outputs.
50
Which of these is the correct expression for the NOT gate?
