Philadelphia University
Student Name:
Faculty of Engineering
Student Number:
Course Title:
Course No:
Lecturer:
Dept. of Computer Engineering
First Exam, First Semester: 2012/2013
19/11/2012
Logic Circuits
Date:
630211
Time Allowed: 60 minutes
Dr. Qadri Hamarsheh
No. Of Pages: 4
Information for candidates
1. This exam paper contains 4 questions totaling 20 marks
2. The marks for parts of question are shown in round brackets.
Advices to candidates
1. You should attempt all sub questions.
2. You should write your answers clearly.
Basic notions: The aims of the questions in this part are to evaluate the required minimal student knowledge and skills.
Answers in the pass category represent the minimum understanding of basic concepts: Digital Systems, Binary Number
Systems, Boolean Algebra and Basic Logic Gates.
Question 1
Multiple Choice
(7 marks)
Identify the choice that best completes the statement or answers the question.
1) Convert 201(3) to base ten:
a)
5
b) 19
c)
8
d) 98
2) The decimal equivalent of the hexadecimal number (F.4)16 is -------.
a)
14.25
b) 15.25
c)
14.75
d) 15.75
3) The BCD code of the decimal number 937.25 is -------.
a)
100100110111.00100101
b) 100011111.010101
c)
1110101001. 11001
d) None of the above
4) The 2's complement representation of 34(10) is:
a)
11011110
b)
01100010
c)
00100010
d)
11100010
̅ + 𝑩) + 𝑪𝑫
̅ , you get:
(𝑨
5) If you apply DeMorgan’s theorem, the complement of the expression ̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅
̅ + 𝑫)
̅ )(𝑪
̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅
(𝑨𝑩
̅+𝑩+𝑪+𝑫
a)
b)
𝑨
̅ + 𝑩)(𝑪𝑫
̅)
̅+𝑫
̅ +𝑪
(𝑨
c)
d)
𝑨+𝑩
6) The equivalent canonical (standard) form for the following logical expression 𝑭 = 𝑨𝑩 + 𝑪 is
̅ 𝑩𝑪 + 𝑨𝑩
̅𝑪 + 𝑨
̅𝑩
̅𝑪
a)
𝑭 = 𝑨𝑩𝑪 + 𝑨
̅
̅
̅
̅
b)
𝑭 = 𝑨𝑩𝑪 + 𝑨𝑩𝑪 + 𝑨𝑩𝑪 + 𝑨𝑩𝑪
̅
̅ 𝑩𝑪 + 𝑨𝑩
̅𝑪 + 𝑨
̅𝑩
̅ 𝑪 + 𝑨𝑩𝑪
c)
𝑭 = 𝑨𝑩𝑪 + 𝑨
d)
None of the above
7) Which of the following is equal to 𝑭(𝑨, 𝑩) = ∑(𝒎𝟎, 𝒎𝟑)
̅ )(𝑨
̅ + 𝑩)
̅+𝑩
̅ )(𝑨 + 𝑩)
(𝑨
a) (𝑨 + 𝑩
b)
̅
̅
̅𝑩
c) (𝑨. 𝑩) + (𝑨. 𝑩)
d)
𝑨𝑩 + 𝑨
1
Question 2
(3marks)
List 6 advantages of digital techniques (systems) compared with analog systems.
Solution
Familiar and Unfamiliar Problems Solving: The aim of the questions in this part is to evaluate that the student has some
basic knowledge of the key aspects of the lecture material and can attempt to solve familiar and unfamiliar problems of
Boolean Expression Simplification, Karnaugh Maps and Logic Diagrams.
Question 3
(7 marks)
̅ 𝐂 + 𝐁𝐂 using Boolean algebra so that the expression is sum of
a) Simplify the Boolean expression 𝐀𝐁 + 𝐀
two products, each product having only two variables.
(2 marks)
Solution
2
b) Write F in Standard (canonical) Sum of Products Form (SOP)
(3 marks)
Solution
̅ + 𝐀
̅ 𝐁 = 𝐀 + 𝐁 using laws of Boolean algebra
c) Proof that 𝐀𝐁 + 𝐀𝐁
Solution
3
(2 marks)
Question 4
For the following circuits,
a) Find an algebraic expression.
b) Put it in SOP form.
(3 marks)
(2 marks)
(1 mark)
Solution
GOOD LUCK
4