Computer Organisation and Architecture Questions & Answers | COA | MCQ

Levels in a Computer System,Parts of a Microprocessor , Conventions, Error Correcting codes, Assembly Language Questions

1. The fundamental conceptual unit in a computer is:
a. CPU
b. Hard Drive
c. Operating System
d. Transistor
2. In a 8086/8088 Microprocessor, the unit responsible for getting the instructions from memory and loading in the Queue is.
a. Execution Unit
b. Registers
c. Stack
d. Bus Interface Unit
3. When you transfer the record from a Big Endian system to a Little Endian system
over the network in order to get the original value, you must:
a. reverse the byte within a word
b. reverse the bytes in an integer
c. reverse the characters in a word
d. there is no simple solution
4. To transmit data bits 1011, the correct even parity seven bit Hamming Code is
a. 0101101
b. 1010101
c. 1100111
d. 0110111
Digital Logic, Addressing Modes etc. (Questions 5 to 8)
5. In a Sequential Logic system, the out put remains even after the input is removed
a. True
b. False
6. The cause of propagation delay is the time it takes a pulse to get through a logic device
a. True
b. False
7. If CS= 24F6 and IP =634A, the physical address is
a. 24F6: 634A
b. 34F5F
c. 2B2AA
d. 24F60
8. The instruction MOV CL, [BX][DI]+8 represents the following addressing mode
a.based relative
b.based indexed
c.indexed relative
d.register indirect
Secondary Storage and Disk Drives – Questions 9-11
9. The amount of time required to read a block of data from a disk into memory is composed of seek time, rotational latency, and transfer time. Rotational latency refers to
a. the time it takes for the platter to make a full rotation
b. the time it takes for the read-write head to move into position over the appropriate track
c. the time it takes for the platter to rotate the correct sector under the head
d. none of the above
10. If a magnetic disc has 100 cylinders, each containing 10 tracks of 10 sectors, and each sector can contain 128 bytes, what is the maximum capacity of the disk in bytes?
a. 128,000
b. 12,800,000
c. 12,800
d. 1,280,000
11. According to the specifications of a particular hard disk a seek takes 3 msecs (thousandths of a second) between adjacent tracks. If the disk has 100 cylinders how long will it take for the head to move from the innermost cylinder to the outermost cylinder.
a. 30 microseconds
b. 300 msecs
c. 3000 msecs
d. 3 microseconds
Parameters: Any questions related to the understanding of disk structure and operation
Primary memory hardware – Questions 12-16
Primary memory is usually implemented using both ROM (Read only memory) and RAM (Random Access memory) chips. Both of these chips provide random access to memory words. The difference between them is that ROM cannot be changed during the normal actions of a program, hence its name, read only memory, while RAM memory may be both read and written. The other difference between them is that RAM memory loses its information when the power is turned off to the chip, but ROM memory does not. For this reason ROM memory is considered non-volatile.
12. What characteristic of RAM memory makes it not suitable for permanent storage?
a. too slow
b. unreliable
c. it is volatile
d. too bulky
13. Part of the operating system is usually stored in ROM so that it can be used to boot up the computer. ROM is used rather than RAM because
a. ROM chips are faster than RAM
b. ROM chips are not volatile
c. ROM chips are cheaper than RAM chips
d. none of the above
14. A given memory chip has 12 address pins and 4 data pins. It has the following number of locations.
a. 24
b. 212
c. 248
d. 216
15. RAM is called DRAM(Dynamic RAM) when
a. a.it is always moving around data
b. b.it requires periodic refreshing
c. it can do several things simultaneously
d. none of the above
16. Which of the following is Non-Volatile memory?
a. EEPROM
b. SRAM
c. DRAM
d. None of the above
Parameters for 5-7: Other characteristics of RAM and ROM chips. The definition of random access.
Internal Representation – Questions 17-22
Computers store all data and instructions as 0’s and 1’s. For this reason the numbers and characters we use to write instructions and data must be translated or encoded as 0’s and 1’s before they can be used in a computer. This encoding is usually called the internal representation of the character or number. In virtually all personal computers, the 7 bit ASCII code is used to internally represent characters. Any positive whole number can be transformed into its binary equivalent, but two’s complement notation is generally used to internally represent integers because of it efficiently represents both positive and negative numbers. Real numbers (fractions) are usually encoded using floating point notation.
17. Two’s complement notation is frequently used for internal representation of
a. fractions
b. integers
c. True and False values
d. floating point numbers
18. If the ASCII code for A is 1000001, B is 1000010, and C is 1000011 then the string 100001110000011000010 represents:
a. CAB
b. BAC
c. CCB
d. ABC
19. The two’s complement representation of –10 is:
a. 11110110
b. 11011001
c. 00001010
d. 11111100
20. The binary representation of 15 is:
a. 01010
b. 01111
c. 10011
d. 00101
21. Floating point representation is used to store
a. Boolean values
b. whole numbers
c. real numbers
d. integers
22. Binary numbers can be used to represent
a.Integers only
b.Fractions only
c.Both fractions and integers
d. both fractions and integers.
Parameters: The numbers or characters to be converted to their internal representation. The order of conversion, i.e. the question may be to convert from two’s complement to an integer.
Computer Buses and performance – Questions 23 – 25
A bus is a set of wires connecting computer components. A computer may have several buses, e.g. a system bus, an internal bus, and special purpose local buses. All communication between the various components takes place over one of these buses. For example, data transfer between the CPU and memory normally occurs on the system bus, while movement of data between registers and the ALU takes place on a bus internal to the microprocessor chip. The speed at which data can be transferred is dependent on the number of data lines in the bus and, in the case of synchronous buses, the clock speed of the bus. The transfer rate or bandwidth of a particular system bus can be calculated from the number of cycles required for transfer, the length of the cycle and the number of data lines. For example, if a bus has 8 data lines, requires 4 cycles to transfer data, and each cycle is 250 nsecs then the bandwidth of the bus is 1 byte per 1000 nsecs. This is equivalent to 1 byte per microsecond or 1 Megabyte /second.
23. In order to execute a program instructions must be transferred from memory along a bus to the CPU. If the bus has 8 data lines, at most one 8 bit byte can be transferred at a time. How many memory access would be needed in this case to transfer a 32 bit instruction from memory to the CPU.
a. 1
b. 2
c. 3
d. 4
24. Suppose that a bus has 16 data lines and requires 4 cycles of 250 nsecs each to transfer data. The bandwidth of this bus would be 2 Megabytes/sec. If the cycle time of the bus was reduced to 125 nsecs and the number of cycles required for transfer stayed the same what would the bandwidth of the bus?
a. 1 Megabyte/sec
b. 4 Megabytes/sec
c. 8 Megabytes/sec
d. 2 Megabytes/sec
25. Any computer must at least consist of
a. Data bus
b. Address Bus
c. Control Bus
d. all of the above
Parameters: different types of buses, length of cycles, number of cycles, number of data lines.
Memory Structure – Questions 26 – 30
Computer memories can vary in the number of addressable units they contain and the size of these addressable units. In many computers the smallest addressable unit is an 8 bit byte. This is not a universal characteristic, however. In some cases the smallest addressable unit is a 4 byte word (32 bits), and there have been computers whose memories were composed of words of size 60. The number of addressable units in a memory determines how many bits are required for a memory address. For example, if a memory contains 64K bytes and a byte is the smallest addressable unit then 16 bits are required for a memory address. On the other hand, if the smallest addressable unit in this memory is a 32 bit word, then 14 bits are required for a memory address.
26. A computer’s memory is composed of 8K words of 32 bits each. How many bits are required for memory address if the smallest addressable memory unit is a word?
a. 13
b. 8
c. 10
d. 6
27. A computer’s memory is composed of 4K words of 32 bits each. How many total bits in memory?
a. 12800
b. 1280000
c. 1310720
d. 131072
28. A computer’s memory is composed of 8K words of 32 bits each, and a byte is 8 bits. How many bytes does this memory contain?
a. 8K
b. 32K
c. 16K
d. 4K
29. A computer’s memory is composed of 8K words of 32 bits each, and the smallest addressable memory unit is an 8 bit byte. How many bits will be required for the memory address?
a. 12
b. 15
c. 13
d. 10
30. A “word” is the natural unit of organization of memory. Different computer types may have different word lengths (in bits) . True or False?
Parameters: Different memory sizes and different addressable unit sizes
Memory Hierarchy – Questions 31 – 38
Computer memory can be viewed as a hierarchy. At the top of the hierarchy is the fastest memory. This memory is usually the smallest and most expensive. Registers and cache memory fall into this category. The next level in the hierarchy is primary memory. This memory is larger than cache memory and is cheaper and slower. At the bottom of the hierarchy is disk storage, which is often called secondary memory. Disk storage is the cheapest and slowest memory. The more immediate the need for the data, the higher in the hierarchy it is stored. For example, data needed for an instruction that is being executed in the CPU is stored in the registers, while data needed for the next few instructions is stored in the cache. Instructions and data which are not immediately required are stored in primary memory or on the disk.
31. Cache memory refers to
a. cheap memory that can be plugged into the mother board to expand main memory
b. fast memory present on the processor chip that is used to store recently accessed data
c. a reserved portion of main memory used to save important data
d. a special area of memory on the chip that is used to save frequently used constants
32. Registers contain data and instructions needed by the CPU. True or False?
33. A computer that is advertised as having a 96K byte DRAM memory and a 2.1 Gigabyte hard drive has
a. 96 K bytes of primary memory and 2.1 Gigabytes of secondary memory
b. 2.1 Gigabytes of primary memory and 96K bytes of secondary memory
c. 96 bytes of cache, 2.1 gigabytes of primary memory
d. 96K bytes of cache, 96 K bytes of primary memory , and 2.1 Gigabytes of secondary memory
34. A memory management technique used to improve computer performance is
a. selecting memory chips based on their cost
b. storing as much data as possible on disk
c. using the cache to store data that will most likely be needed soon
d. preventing data from being moved from the cache to primary memory
Parameters: Any question about the function of caches, registers, primary and secondary memory.
35. The fetch-decode-execute cycle refers to the process by which data is read from the hard drive and stored in memory. True or False?
36. Interrupts can be generated in response to
a. detected program errors such as arithmetic overflow or division by zero
b. detected hardware faults
c. Input/Output activities
d. Internal timers
e. b, c, and d
f. a, b, c, and d
37. Virtually all computer designs are based on the von Neumann architecture. A high level view of this architecture has the following three components:
a. Buses, memory, input/output controllers
b. Hard disks, floppy disks, and the CPU
c. memory, the CPU, and printers
d. memory, input/output modules, and the CPU
38. Which of the following programming languages has an instruction set closest to the machine language of a computer?
a. BASIC
b. Fortran
c. Assembly Language
d. C++
History of Computing – Question 39 – 40
39. The first person who published paper on using computers to perform tasks other than computations is
a. Charles Babbage
b. Lady Lovelace
c. Alan Turing
d. Konrad Zuse
40. What was the name of the government funded computer used during World War II to compute firing tables?
a. VAX computer
b. IBM computer
c. Colossus computer
d. ENIAC computer
Parameters: Any questions related to the evolution of computer technology
General questions about Operating Systems – Questions 41 to 43
41. Which of the following started out as separate program from operating systems but usually is included as part of the OS later on?
a. Text Editor
b. Command processor
c. Resource allocator
d. Dispatcher
42. An operating system that allows several processors to perform computation as the same time is call
a. Single program
b. Multitasking
c. Multiprocessing
d. Real time processing
43. The kind of interface with icons and menu bars for user to point at with mouse instead of entering commands for operating system to perform certain tasks is called
a. GUI
b. Command line interface
c. User friendly programming
d. None of the above
Parameters: Other general questions regarding the functions, components and operations of an operating system may be asked.
Computer Ethics – Question 44 to 46
44. he prime targets of software pirates are
a. programs written for mainframes
b. games and application programs for microcomputers
c. programs in the public domain
d. none of the above
45. Considering the impacts computer technology has on modern society, which of the following is negative?
a. People can communicate with each other without geographical limitations
b. Stock brokers do not need to be in a central place for trading
c. More people totally rely on computers when doing their works
d. Information can reach different area and people at light speed
46. A student retrieve a copy of a program assignment from the recycle bin in the computer lab and use the code to complete his own program assignment. His action is considered
a. legal but unethical
b. illegal and unethical
c. legal and ethical
d. illegal but ethical
Parameters: Any questions related to the topic may be