Octal Number System:
It is a system with base 8. This number system has 8 digits from (0-7). It is a shorthand method of expressing binary quantities.
In this system, there exist 8 combinations of 3-bit binary numbers.
The octal number (20)8 can be converted to a decimal number as follows:
(20)8 = 2 * 81 +0 * 80
= 16+0
= (16)10
The differences between the Binary Number System and Decimal Number System are as follows:
|
Binary Number System |
Decimal Number System |
|
1) It is a number system with base 2. |
1) It is a number system with base 10. |
|
2) This number system contains only two digits, i.e., 0 and 1. |
2) It contains digits from (0-9). |
|
3) The output of this system is only in two digits, i.e., 0 and 1. |
3) Here, the output is in integer value. |
|
4) It is more efficient. |
4) It is less efficient. |
|
Decimal |
Binary |
Octal |
Hexadecimal |
|
0 |
0000 |
0 |
0 |
|
1 |
0001 |
1 |
1 |
|
2 |
0010 |
2 |
2 |
|
3 |
0011 |
3 |
3 |
|
4 |
0100 |
4 |
4 |
|
5 |
0101 |
5 |
5 |
|
6 |
0110 |
6 |
6 |
|
7 |
0111 |
7 |
7 |
|
8 |
1000 |
10 |
8 |
|
9 |
1001 |
11 |
9 |
|
10 |
1010 |
12 |
A |
|
11 |
1011 |
13 |
B |
|
12 |
1100 |
14 |
C |
|
13 |
1101 |
15 |
D |
|
14 |
1110 |
16 |
E |
|
15 |
1111 |
17 |
F |
A. memory refreshing time.
B. memory access time.
C. memory output time.
D. memory scheduling time.
The amount of time that it takes for the memory to produce the data required, from the start of the access until when the valid data is available for use, is called the memory's access time, sometimes abbreviated as ta.
A. Dot Matrix Printer.
B. Data Modulation Printer.
C. Data Matrix Printer.
D. Dot Modulation Printer.
A dot matrix printer is a most popular serial printer i.e., it prints one character at a time.
A. floppy disk.
B. pen drive.
C. magnetic tape.
D. RAM.
Magnetic tape has been used for data storage for over 50 years.
A. abacus.
B. digital computer.
C. analog computer.
D. supercomputer.
It is a form of computer that uses continuous physical phenomena such as electrical and mechanical quantities to model the problem being solved.
A. impact printer.
B. non-impact printer.
C. electrostatic printer.
D. electromagnet printer.
In impact printer, there is a mechanical contact between the print head and the paper.
A. monitor.
B. speaker.
C. MICR.
D. printer.
MICR stands for Magnetic Ink Character Reader. It is a character reading technology adopted mainly by the banking industry to facilitate the processing of cheques.
A. USB port.
B. parallel port.
C. serial port.
D. AGP port.
Parallel ports can send or receive a byte (8 bit) at a time. Unlike, the serial port these 8 bits are transmitted parallel to each other.
A. USB port.
B. parallel port.
C. serial port.
D. AGP port
A serial port is a serial communication physical interface through which information transfers in or out one bit at a time.
A. serial port.
B. parallel port.
C. bluetooth.
D. USB port.
A parallel port is a type of interface found on computers for connecting various peripherals.
A. serial ports.
B. AGP ports.
C. parallel ports.
D. IR ports
Parallel ports can send or receive a byte (8 bits) at a time. Unlike the serial port, these 8 bits are transmitted parallel to each other.
A. 39.
B. 43.
C. 41.
D. 42.
1x(2^0) +1x(2^1)+0x (2^2) + 1x (2^3) + 0x(2^4) + 1x(2^5)=43.
A. 10001010.
B. 10010010.
C. 10100100.
D. 11011100.
Divide successively by 2 and write the remainders from bottom to up.
A. 168.
B. 169.
C. 170.
D. 171.
Multiple each digit with the weights of 2.
A. AAB.
B. ABC.
C. ADC.
D. AEF.
Group the number into fours. Write the corresponding hexadecimal equivalent.
A. AE.
B. AB.
C. DF.
D. AC.
Group the number into fours. Write the corresponding hexadecimal equivalent. Here binary number 1010 = A and 1011 = B
A. 1011010.
B. 1000001.
C. 1000001.
D. 0100110.
Divide successively by 2 and write the remainders from bottom to top.
A. 1010101.
B. 0101001.
C. 1101010.
D. 11000111.
Divide successively by 2 and write the remainders from bottom to top.
A. EC.
B. EB.
C. E
A.
D. ED.
Group the number into fours. Write the corresponding hexadecimal equivalent.
A. BAD.
B. BAF.
C. BDF.
D. BCE.
Group the number into fours. Write the corresponding hexadecimal equivalent. 1011 1010 1111 is equivalent to B A F.
A. 101101.
B. 010100.
C. 110011.
D. 010011.
Divide successively by 2 and write the remainders from top to down.
A. 1100100.
B. 0101010.
C. 1110000.
D. 0101011.
Divide successively by 2 and write the remainders from top to down.
A. 34AB.
B. 32BD.
C. 37AE.
D. 35AC.
First of all, grouping of numbers in four digits group is done, i.e., 11,0111,1010,1110. The number is converted to 37AE. Thus, the solution is 37AE.
A. 11110101.
B. 11101010.
C. 11101111.
D. 11101110.
The positive expression of number is 00010001. Its complement is 11101110.
A. AF.
B. AB.
C. AC.
D. AD.
Group the number into fours. Write the corresponding hexadecimal equivalent.
A. positional value system.
B. postfix system.
C. prefix system.
D. binary fix system.
The hexadecimal system is also a positional value system, wherein each hexadecimal digit has its own value or weight expressed as a power of 16.
A. bin.
B. bit.
C. bidi.
D. bd.
Bit is a binary digit, taking a logical value of either "1" or "0" (also referred to as "true" or "false" respectively). Binary digits are a basic unit of information storage and communication in digital computing and digital information theory.
A. base-10 system.
B. base-9 system.
C. prefix system.
D. binary fix system.
The decimal system is composed of 10 numerals or symbols. These 10 symbols are 0,1,2,3,4,5,6,8,9; using these symbols as digits of a number, we can express any quantity.
A. More Standard Digit.
B. Most Standard Digit.
C. More Significant Digit.
D. Most Significant Digit.
The rightmost digit of a decimal number is known as the Most Significant Digit.
A. Lower Standard Digit.
B. Least Standard Digit.
C. Lower Significant Digit.
D. Least Significant Digit.
The leftmost digit in a decimal number is referred to as the Least Significant Digit.
A. separate the MSD and LSD of the number.
B. separate the integer and fractional part of the number.
C. separate the integer and binary part of the number.
D. separate the binary and fractional part of the number.
In 25.12, the decimal point is used to separate 25 and 12, i.e., integer and fractional part of the number.
A. AB2.
B. 2AB.
C. 2B
A.
D. BA2.
Group into 4 and express the groups in hexadecimal. 1010 = A, 1011 = B and 01 = 2
A. 13643 .
B. 36477 .
C. 13640 .
D. 16473 .
Divide into groups of three starting from left to right and express the groups in decimal. 1011110100011 can be grouped as 1 011 110 100 011, i.e., 13643
A. 39.
B. 40.
C. 41.
D. 42.
0x(2^0) +1x(2^1)+0x (2^2) + 1x (2^3) + 0x(2^4) + 1x(2^5)=42.
A. 1010101.
B. 0101001.
C. 1101010.
D. 1110100.
Divide successively by 2 and write the remainders from top to down.
A. 10001010.
B. 10010010.
C. 01010101.
D. 11011100.
Divide successively by 2 and write the remainders from top to down.
A. 11100001.01011.
B. 10100101.01011.
C. 11000101.01011.
D. 10110100.01011.
Convert 225 to binary and then .35 to its binary equivalent. Divide 225 by 2 and multiply .35 by 2 and collect all numbers to the left of the decimal point, reading down.
A. 0110010.
B. 0110011.
C. 0110000.
D. 0001011.
Decimal numbers are represented in ASCII starting from 011.
A. 2^31.
B. 2^32-1.
C. 2^31-1.
D. 2^32.
In n bits format, one can store 2^n-1 bits.
A. reversing (inverting) the bits and adding 1.
B. adding 1 and reversing the bits.
C. calculating the integer's additive inverse.
D. changing the highest bit to a 1.
To obtain the 2’s complement of a number, first reverse the bits and then add 1 to it.
A. –127 to 127.
B. 0 to 127.
C. 0 to 270.
D. –32768 to 32767.
ASCII code is a 7-bit code. It codes 2^7 bits ranging from 0 to 127.
A. ASCII.
B. ISCII.
C. Unicode.
D. extended ASCII.
Java code is written in Unicode to make it a portable language.
A. 2.
B. 7.
C. 16.
D. 8.
FF is a hexadecimal representation.
A. 66D.
B. 41H.
C. 100 0001.
D. 110 0001.
ASCII code is a 7-bit code.
A. 15.
B. 16.
C. 17.
D. 18.
In hexadecimal number system, F represents 15.
A. 12 bits.
B. 4 bits.
C. 16 bits.
D. 8 bits.
A byte is a unit of information storage in computers. 8 bits make 1 byte.
A. 2.
B. 16.
C. 8.
D. 4.
It uses the digits 0 to 7. Numerals can be made from binary numerals by grouping consecutive binary digits into groups of three.
A. decimal number system.
B. binary number system.
C. hexadecimal number system.
D. octal number system.
The machine language converts the numbers in binary format as computer understands only binary form, i.e., 0 and 1.
A. 6.
B. 7.
C. 8.
D. 15.
An octal number system has 2^3=8 digits.
A. 4B3E.
B. 37AE.
C. EA73.
D. E3B4.
Group into four and write their hex equivalent. 11011110101110 can be divided as 11 0111 1010 1110 which is equal to 3 7 A E .
A. 10110.01.
B. 01011.11.
C. 11001.01.
D. 10101.10.
The machine first converts 22 into binary, then .25 into binary equivalent.
This is the conventional form for number representation. Integers are identified by their signs (+ or -) & a string of digits, which represent the magnitude.
For example:
+18 or 46 are Positive Integers.
-16 or –78 are Negative Integers
For example: +15 will be represented in following way.

Each hex digit is converted to its 4-digit binary equivalent.
For example:
(9F2)16 = 9 F 2
1. First convert the decimal number to its binary equivalent by repeated division method.
Groups in forms 10, 1011, 1010
Convert each number 2, B, A
It will be converted as follows:
(56.08) 16 = 5 x (16) 1 + 6 x (16) 0 + 0 x (16)-1 + 8 x (16)-2
= 80 + 6 + 0 + 8/256
= 86 + 0.03125
= (86.03125) 10
A hex digit position has a weight that is a power of 16. The LSD has a weight of 160 = 1, the next higher digit has a weight of 161 = 16, the next higher digit has a weight of 162 = 256, and so on. For example:
(356) 16 = 3 x (16) 2 + 5 x (16) 1 + 6 x (16) 0
= 768 + 80 + 6
= (854) 10

Decimal to hexadecimal can be done by using repeated division by 16.

The procedure followed to convert a binary to its octal equivalent is simply reverse of what we follow for binary to octal conversions. The bits of the binary integer are grouped into groups of three bits each starting at the LSB. Then, each group is converted to its octal equivalent.
The conversion from octal to binary is performed by converting each octal digit to its 3-digit binary equivalent. The eight possible digits are converted as in the table below :
|
Octal Digit
|
0
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
|
Binary Equivalent
|
000
|
001
|
010
|
011
|
100
|
101
|
110
|
111
|
An octal number can be converted to its decimal equivalent by multiplying each octal by its positional weight.
(372) 8 = 3 x (8)2 + 7x (8)1 + 2 x (8)0
= 3 x 64 + 7 x 8 + 2 x 1
Original number is 0.375, Integer Part
Multiply (fractional part) 0.015625 by 8 = 0.125 0
Multiply (fractional part) 0.125 by 8 = 1.0 0![]()
Reading down,
(0.015625) 10 = (0.01) 8
= 1 x (2) 3 + 1 x (2) 2 + 0 x (2) 1 + 1 x (2) 0 + 0 x (2)-1 + 0 x (2)-2 + 0 x (2)-3 + 1 x (2)-4 + 0 x (2)-5 + 1 x (2)-6
= 8 + 4 + 0 + 1 + 0 + 0 + 0 + 1/16 + 0 + 1/64
= 13 + 0.0625 + 0.015625
= (13.078125) 10
(1101.000101) 2 = (13.078125) 10

In this method, the number is divided again & again by 2, & its remainders are recorded, until the remainder becomes zero. The final binary result is obtained by assembling all the remainders, with the last remainder, with the last remainder being the most significant bit (MSB).
(11011) 2 (binary)
(2) 4 + (2) 3 + (2) 2 + (2) 1 + (2) 0 = 16+8+2+1
A. serial ports.
B. AGP ports.
C. parallel ports.
D. IR ports.
Serial ports transfer data serially a bit at a time. Serial ports provide a standard connector and protocol to let you attach devices, such as modems, to your computer.
A. serial ports.
B. AGP ports.
C. parallel ports.
D. IR ports.
It is a serial communication physical interface through which information transfers in or out one bit at a time.
A. CPU.
B. memory.
C. interface.
D. port.
A port serves as an interface between the computer and other computers or peripheral devices.
A. Digitized Video Diskette.
B. Digital Video Disk.
C. Digital Video Diskette.
D. Digitized Video Disk.
Digital Video Disk or DVD is an optical disc storage media format. DVD's were originally developed for the movie industry. Huge capacity makes them attractive for storing large amounts of data.
A. bit length.
B. word length.
C. byte.
D. address.
The number of bits a memory word consists of is known as word length. Memory addresses are consecutive numbers, starting with the address 0, 1, 2, ... and running upto the largest addresses. Thus, at address 0, we find the first word; at address 1, the second word; at address 2, the third word; at address 3 and so on.
A. hard disk.
B. ports.
C. compact disk.
D. disk drives.
A port is an application-specific or a process-specific software construct to serve as a communications endpoint used by transport layer protocols of the Internet Protocol Suite such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP).
A. printer.
B. scanner.
C. joy stick.
D. light pen.
A scanner scans an image and we can save it on a computer.
A. floppy disk.
B. hard disk.
C. CDROM.
D. tape drive.
CDROM is used to store information and cannot be used to modify it.
A. any device that is designed to store data such as a printer.
B. an input device.
C. an output device.
D. any device that is designed to store data such as a hard drive.
A data storage device is used to store data and its related information.
A. transistors.
B. MOSFET.
C. capacitors.
D. resistors.
A DRAM needs to be refreshed because the capacitors lose their charge over time.
A. bytes.
B. word strength.
C. word length.
D. memory space.
Word Length is the number of bits in a word. It stores the information in the word. The amount of information is the word length.
A. binary digit.
B. binary data.
C. byte data.
D. Bit data.
A bit is a binary digit, taking a value of either 0 or 1. Binary digits are a basic unit of information storage and communication in digital computing.
A. electromagnetic printers.
B. laser printers.
C. inkjet printers.
D. electrostatic printers.
Electrostatic printers are instruments, which are used to print an optical image on a specially treated paper. Electro-statically charged and uncharged portions of the paper illustrate light and dark portions of the original image.
A. secondary memory.
B. cache memory.
C. DRAM.
D. main memory.
It is a storage device used by a computer to hold the currently executing program and its working data.
A. External Data Output DRAM.
B. External Data Out DRAM.
C. Extended Data Out DRAM.
D. Extended Data Output DRAM.
It is a short form for Extended Data Out Dynamic Random Access Memory. Conventional DRAM cells discharge after each read operation and requires refreshing time before it can be read again.
A. 1.44 MB.
B. 700 MB.
C. 40 GB.
D. 10 MB.
A floppy disk is a data storage medium that is composed of a disk of thin, flexible ("floppy") magnetic storage medium encased in a square or rectangular plastic shell. It can store upto 1.44 MB of data.
A. CD-R.
B. CD-ROM.
C. CD-RW.
D. floppy disk.
CD-RW is erasable disk. It can also be called as the rewritable media.
A. bluetooth.
B. USB.
C. AGP.
D. PS/2.
Bluetooth provides an agreement at the protocol level, where products have to agree on when bits are sent, how many will be sent at a time and how the parties in conversation can be sure, that the message received is the same as the message sent.
A. bluetooth.
B. PS/2 port.
C. serial port.
D. parallel port.
A PS/2 (Personal System/2) port is an electronic receptacle or plug found on computers. It accepts a PS/2 with a mini-DIN connector and is most often used to plug in a keyboard or mouse.
A. USB.
B. AGP.
C. Infrared Ports.
D. bluetooth.
IR Ports are special type of ports in which a focused ray of light is modulated with information.
We can represent an integer in the following ways :
a.
b.
c. Two’s compliment representation