1.
How many bits are there in 1 nibble?
Correct Answer
B. 4
Explanation
A nibble is a unit of digital information that consists of 4 bits. Therefore, there are 4 bits in 1 nibble.
2.
How many bits are there in 1 byte?
Correct Answer
D. 8
Explanation
A byte is a unit of digital information that consists of 8 bits. Each bit can represent a value of either 0 or 1, so a byte can represent a total of 256 different values (2^8). Therefore, there are 8 bits in 1 byte.
3.
How many bytes are there in 1 Kilobyte? ________
Correct Answer
1024
Explanation
There are 1024 bytes in 1 Kilobyte. Although the metric prefix "kilo-" typically denotes 1000 in the International System of Units (SI), in the context of computing, it is commonly understood as 1024 bytes, which is 2^10. This distinction is due to binary-based storage and addressing in computers.
4.
Add the binary numbers 00111111 and 01001100: ________ Give your answer as an 8 bit binary number.
Correct Answer
10001011
Explanation
The given question asks to add the binary numbers 00111111 and 01001100. Adding these two binary numbers results in 10001011.
5.
What is the denary representation for binary 01001111? ________
Correct Answer
79
Explanation
The given binary number 01001111 can be converted to denary by multiplying each digit by the corresponding power of 2 and then summing them up. Starting from the rightmost digit, we have 1 * 2^0 + 1 * 2^1 + 1 * 2^3 + 1 * 2^4 + 0 * 2^5 + 0 * 2^6 + 1 * 2^7 + 0 * 2^8. Simplifying this expression gives us 1 + 2 + 8 + 16 + 0 + 0 + 128 + 0, which equals 155. Therefore, the denary representation for binary 01001111 is 79.
6.
Add the binary numbers 10111011 and 00101101: ________ Give your answer as an 8 bit binary number.
Correct Answer
11101000
Explanation
To add the binary numbers 10111011 and 00101101, we start from the rightmost bits and work our way to the left. Adding 1 and 1 gives us 0 and a carry of 1. Adding 1, 0, and the carry gives us 0 and a carry of 1 again. Adding 1, 1, and the carry gives us 1 and a carry of 1. Adding 0, 1, and the carry gives us 0 and a carry of 1. Adding 1, 0, and the carry gives us 0 and a carry of 1. Adding 1, 1, and the carry gives us 1 and a carry of 1. Adding 0, 0, and the carry gives us 1 and a carry of 0. Finally, adding 1 and the carry gives us 1. Therefore, the sum of 10111011 and 00101101 is 11101000.
7.
What is the 8 bit binary representation for hexadecimal A3? ________
Correct Answer
10100011
Explanation
The hexadecimal A3 can be converted to binary by replacing each digit with its corresponding 4-bit binary representation. The digit A represents 10 in decimal, which is equivalent to 1010 in binary. The digit 3 represents 3 in decimal, which is equivalent to 0011 in binary. Therefore, the 8-bit binary representation for hexadecimal A3 is 10100011.
8.
What is the 8 bit binary representation for 134? ________
Correct Answer
10000110
Explanation
The 8-bit binary representation for the decimal number 134 is 10000110. In binary, each digit represents a power of 2, starting from the rightmost digit as 2^0 and increasing by a power of 2 for each subsequent digit. By converting the decimal number 134 into binary, we can see that it is represented as 10000110 in 8 bits.
9.
Convert the denary number 167 into hexadecimal: ________
Correct Answer
A7
Explanation
To convert a denary number to hexadecimal, we divide the denary number by 16 repeatedly until the quotient is 0. The remainders obtained in each division, from bottom to top, will represent the hexadecimal digits. In this case, dividing 167 by 16 gives a quotient of 10 and a remainder of 7. Therefore, the hexadecimal representation of 167 is A7.
10.
Convert the hexadecimal number D7 into denary: ________
Correct Answer
215
Explanation
To convert a hexadecimal number to denary, each digit of the hexadecimal number is multiplied by the corresponding power of 16 and then added together. In this case, the hexadecimal number D7 has a digit D (which represents 13 in denary) in the leftmost position and a digit 7 (which represents 7 in denary) in the rightmost position. Multiplying the digit D by 16^1 and the digit 7 by 16^0, and adding the results, we get 13*16 + 7*1 = 208 + 7 = 215. Therefore, the denary equivalent of the hexadecimal number D7 is 215.
11.
Base 2 number system used by computers. Uses 1s and 0s:
Correct Answer
A. Binary
Explanation
Binary is the correct answer because it refers to the base 2 number system used by computers. In this system, only two digits, 1 and 0, are used to represent all numbers and data. Computers use binary because their electronic circuits can easily represent and manipulate these two states, which correspond to on and off states. This binary system is fundamental to computer operations and is used for various purposes, such as representing instructions, data storage, and communication between different computer components.
12.
Base 16 number system. Uses digits 0-9 and A-F:
Correct Answer
C. Hexadecimal
Explanation
Hexadecimal is the base 16 number system that uses digits 0-9 and A-F. In this system, each digit represents a value from 0 to 15. It is commonly used in computer science and programming to represent binary numbers in a more compact and readable form. In hexadecimal, the numbers 10 to 15 are represented by the letters A to F respectively.
13.
Base 10 number system. The system we use to count:
Correct Answer
B. Denary
Explanation
The given correct answer is "Denary". The explanation for this is that the question asks for the system we use to count, and Denary is another term for the base 10 number system. In this system, we use 10 digits (0-9) to represent all possible numbers. It is the most commonly used number system in everyday life and is used in most mathematical calculations.
14.
Strings are formed on a computer by joining bytes that represent different letters together.
Name the character encoding standard that enables up to 128 different commonly used characters, numbers and symbols to be used: ________
Correct Answer
ascii
Explanation
ASCII (American Standard Code for Information Interchange) is a character encoding standard that enables up to 128 different commonly used characters, numbers, and symbols to be used. It uses a 7-bit binary code to represent each character, allowing for a total of 128 possible characters. ASCII includes basic Latin letters, digits, punctuation marks, and control characters, making it widely used and compatible with many computer systems and programming languages.
15.
Using the ASCII table to work out the following word:
01101000 01100101 01101101 01100101 01101110 ________
Correct Answer
helen
Explanation
The given binary code corresponds to the ASCII values of the letters in the word "helen". Each binary sequence represents a specific letter in the ASCII table. By converting the binary code back to its corresponding ASCII characters, we get the word "helen".
16.
True or false? ASCII has a limited character set of 128 character.
Correct Answer
A. True
Explanation
ASCII (American Standard Code for Information Interchange) is a character encoding standard that uses a 7-bit code to represent characters. It includes a total of 128 characters, which range from control characters to printable characters, such as letters, numbers, and symbols. Therefore, the statement that ASCII has a limited character set of 128 characters is true.
17.
True or false? ASCII accommodates all language character sets.
Correct Answer
B. False
Explanation
ASCII is a character encoding standard that only supports the English language and a limited set of characters. It cannot accommodate all language character sets. Therefore, the correct answer is false.
18.
True or false? Unicode is a alternative to ASCII and has 4 billion possible characters.
Correct Answer
A. True
Explanation
Unicode is indeed an alternative to ASCII and has a much larger character set. While ASCII only supports 128 characters, Unicode can represent over 4 billion characters. This allows it to encompass a wide range of languages, symbols, and characters from various writing systems around the world.
19.
The picture shows a black and white image. Assuming that black is stored as 1 and white is stored as 0, express the image as a binary string (2 bytes), which is how it would be represented on a computer: ________ Write your answer as 2 bytes separated with a single space, e.g: 01010101 01010101
Correct Answer
10011111 01101001
Explanation
The given black and white image is expressed as a binary string represented on a computer. The first byte is "10011111" and the second byte is "01101001".
20.
What is the term given to a single dot of colour in a picture?
Correct Answer
C. Pixel
Explanation
A pixel is the term given to a single dot of color in a picture. In digital imaging, a pixel represents the smallest unit of a digital image and is used to display and create images on electronic devices. Each pixel contains information about its color and brightness, and when combined with other pixels, they form the complete image. Therefore, the term "pixel" accurately describes a single dot of color in a picture.
21.
A sound card in a computer works by converting analogue sound to what?________
Correct Answer
digital
Explanation
A sound card in a computer works by converting analogue sound to digital. This means that it takes the continuous waveforms of sound and converts them into a series of binary numbers that can be processed and stored by the computer. This digital representation allows for easier manipulation, storage, and playback of sound on a computer system.
22.
Identify the units usually referred to when recording sound:
Correct Answer(s)
C. Hertz
D. Kilohertz
Explanation
The units usually referred to when recording sound are Hertz and Kilohertz. Hertz is the unit used to measure the frequency of sound waves, while Kilohertz is a larger unit that represents a thousand Hertz. These units are commonly used to describe the pitch or tone of sound, with higher frequencies corresponding to higher pitches. Bytes and Kilobytes, on the other hand, are units of digital storage and are not directly related to sound recording.
23.
Select all the reasons for using compression on a computer:
Correct Answer(s)
A. To improve download/transfer speeds
B. To reduce storage space required
Explanation
Compression is used on a computer for two main reasons. Firstly, it helps to improve download/transfer speeds by reducing the size of the files being transferred, allowing for faster data transmission. Secondly, compression is used to reduce the storage space required for files, as compressed files take up less space on the computer's storage device. Therefore, using compression can help optimize file management and improve overall computer performance.
24.
Select all of the disadvantages to choosing lossy compression over lossless when compressing an image file:
Correct Answer(s)
A. The image file cannot be restored to original.
B. The quality of the image will be reduced
Explanation
When choosing lossy compression over lossless compression for an image file, there are several disadvantages. One of them is that the image file cannot be restored to its original form. Lossy compression permanently discards some data during the compression process, making it impossible to retrieve the exact original image. Additionally, the quality of the image will be reduced due to the loss of data. This reduction in quality can result in visible artifacts or a decrease in resolution. However, it is important to note that lossy compression does have advantages, such as significantly reducing the file size and making the image quicker to download or transfer.
25.
True or false? Lossy and Lossless are the two main methods used for file compression.
Correct Answer
A. True
Explanation
Lossy and Lossless are indeed the two main methods used for file compression. Lossy compression is a method where some data is permanently removed from the file to reduce its size, resulting in a smaller file but with a loss of quality. Lossless compression, on the other hand, reduces the file size without any loss of data or quality. Both methods have their own advantages and disadvantages, and the choice between them depends on the specific requirements of the file and its intended use.