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