Computer Science for IGCSE & O level - Boolean Logic (Section 3)
1
Which of the following is an application of logic gates?
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(D)
All of the above
2
In digital circuits, what does 'HIGH' voltage typically represent?
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(B)
1
3
Which of the following best describes the operation of a NAND gate?
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(A)
An AND gate followed by a NOT gate.
4
In the engine management system example, which combination of conditions would *NOT* trigger the warning light to activate?
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(B)
Motor speed = 2500 rpm, bearing temperature = 85°C, water velocity = 6 m/s
5
What is the simplified expression for (A + B)' using DeMorgan's Theorem?
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(B)
A' * B'
6
Which of the following statements best describes the purpose of a logic gate?
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(B)
To combine one or more inputs to produce an output based on a specific rule.
7
Based on the image, which Boolean expression matches the following truth table:
| A | B | Output |
|---|---|--------|
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 0 |
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(C)
A XOR B
8
What is the output of the logic expression A . 1?
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(C)
A
9
Which gate is used to determine the sum of two binary digits?
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(C)
XOR gate
10
What is the purpose of a truth table when designing a logic circuit?
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(A)
To test and confirm the intended logic of the circuit.
11
What is the relationship between the inputs and the output in a NOT gate?
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(B)
The output is the inverse of the input
12
If the output of a logic gate is always 1, regardless of the input, what type of logic gate is it?
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(D)
None of the above
13
If A = 1, what is the value of A'?
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(A)
0
14
What operation does the OR gate perform in Boolean algebra?
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(B)
Logical addition
15
What is the role of a logic expression in the context of circuit design?
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(B)
To represent the circuit's operation using mathematical notation.
16
Which of the following statements is true about the XOR gate?
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(C)
Output is HIGH if inputs are different
17
If the input to an AND gate are A=1 and B=0, what will be the output?
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(A)
0
18
In the engine management system example, the output Y is '1' under specific conditions. If the motor speed = 3000 rpm and bearing temperature is 90°C, and water velocity is 5 m/s, what is the output?
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(B)
0
19
In the engine management system, what would be the output (Y) if: Motor speed = 3000 rpm, Bearing Temperature = 75°C, Water velocity = 5 m/s?
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(B)
1
20
If a circuit is meant to turn on an output when either input A or input B is true, what type of gate would most likely be utilized?
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(B)
OR gate
21
What is the main advantage of using NAND gates in building logic circuits?
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(B)
They can be used to construct all other basic logic gates.
22
What does the XOR gate's output represent?
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(B)
The logical difference between the inputs.
23
What does the '¬' symbol represent in Boolean algebra?
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(C)
NOT
24
Which gate is referred to as 'Inverter'?
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(C)
NOT gate
25
What does the term 'logic level' refer to in digital electronics?
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(B)
The voltage of a signal
26
Which of the following Boolean expression is equivalent to the NAND gate?
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(B)
(A . B)'
27
What is the main advantage of using a truth table to assist in circuit design, based on the given examples?
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(B)
It helps verify the correctness of the circuit by defining all outputs.
28
What does a NOT gate do?
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(A)
Inverts the input
29
What type of operation is represented by (A AND B)'?
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(A)
NAND
30
In the context of logic circuits, what is a truth table used for?
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(C)
To show the outputs of a logic circuit for different input combinations.
31
What is the inverse of the AND gate?
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(B)
NAND gate
32
What is the output of the logic expression: A . 0?
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(A)
0
33
Which of the following options represents the NOT operation?
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A
B
C
34
In the context of Boolean algebra, the OR operation can be best described as:
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(B)
Only the output is 1 when any one or both inputs are 1
35
A logic circuit has three inputs: A, B, and C. The output is high (1) if and only if A and B are both high. Which logic gate would you need, along with another gate or two?
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(A)
AND
36
What is the name of the gate which gives the inverted output of an OR gate?
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(C)
NOR gate
37
What is the purpose of a truth table in digital logic?
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(B)
To show the possible outputs of a logic gate for all possible input combinations.
38
What is the output of an AND gate if input A is 1 and input B is 0?
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(A)
0
39
What is the output of a NAND gate if both inputs are 1?
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(A)
0
40
How can we express NOT (A AND B) in Boolean algebra?
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(C)
A' + B'
41
Which of the following logic gates is represented by the Boolean expression: Y = A + B?
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(B)
OR
42
Which of the following are true about the use of NAND gates in building circuits?
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A
B
C
43
How many inputs does an OR gate typically have?
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(B)
2
44
Which of the following operations does an XOR gate perform?
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A
D
45
Which of the following correctly describes the function of a half-adder circuit?
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(B)
It adds two binary digits and produces a sum and a carry-out.
46
What type of gate inverts the input signal?
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(C)
NOT
47
In the turbine example, what is the output of the system?
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(C)
A binary value.
48
In the context of Boolean algebra, which operation is represented by the '+' symbol?
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(B)
OR
49
In the turbine example, the value of K (the output) is determined by which condition?
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(A)
Whether turbine speed is greater than 1000rpm and/or the bearing temperature is 80°C.
50
What is the relationship between the inputs and outputs of a logic circuit best described by?
