Read the text and choose the best way to complete the sentences that follow according to the text.
Bits – basic units of memory
Information is processed and stored in computers as electrical signals. A computer contains thousands of
electronic circuits connected by switches that can only be in one of two possible states. ON (the current is
flowing through the wire) or OFF (the current is not flowing through the wire). To represent these two
conditions we use the binary notation in which 1 means ON and 0 means OFF. This is the only way a
computer can ‘understand’ anything. Everything about computers is based upon the binary process. Each 1 or 0
is called binary digit or bit.
Bytes and characters
1s and 0s are grouped into eight-digit codes that typically represent characters (letters, numbers and symbols).
Eight bits together are called a byte. Thus, each character in a keyboard has its own arrangement of eight bits.
For example, 01000001 for the letter A, 01000010 for B and 01000011 for C.
The ASCII code
The majority of computers use a standard system for the binary representation of characters. This is the
American Standard Code for Information Interchange, known popularly as ‘ASCII’ (pronounced ask-key).
There are 256 different ways of combining 0 and 1 bits in a byte. So they can give us 256 different signals.
However, the ASCII code only uses 128 bytes to represent characters. The rest of the bytes are used for other
purposes.
The first 32 codes are reserved for characters such as the Return Key, Tab, Escape etc. Each letter of the
alphabet, and many symbols (such as punctuation marks), as well as the ten numbers, have ASCII
representations. What makes the system powerful is that these codes are standard.
Kilobytes, Megabytes and Gigabytes
In order to avoid astronomical figures and sums in the calculation of bytes, we use units such as kilobytes,
megabytes and gigabytes. One kilobyte is 1,024 bytes (210) and is represented as KB, or more informally as K.
One megabyte is equivalent to 1,024 KB, and one gigabyte is 1,024 MB.
We use units (KB, MB, GB) to describe the RAM memory, the storage capacity of disks and the size of any
application or document.
1. One bit is …in the binary notation system.
a) 1 or 0
b) 1 and 0 together
c) 1
2. Thousands of electronic circuits in a computer produce …
a) switches
b) electrical signals
c) information
3. Letters are represented by …
a) two bytes b) eight bytes
c) eight bits
4. Characters in the ASCII code are represented by ……
a) 256 bytes
b) 128 different combinations of 1 and 0
c) 128 bits
5. MBs and GB are used to define the ….
a) quality of a document
b) size of a document
c) the position of a document
Choose the best word to complete the sentence
1. Vision is _______________ because we perceive infinitely smooth gradations of shapes and colours.
a) digital
b) analogical
c) binary
d) decimal
2. A _____________ analogue device is a clock in which the hands move continuously around the face.
a) used
b) useful
c) typical
d) typed
3. A digital device processes _______________ information and more generally manipulates symbolic
information
a) numerical
b) numeral
c) number
d) decimal
4. A digital computer is an electronic computing machine that uses the binary ____________.
a) numbers
b) digits
c) gradations
d) charges
5. Sequences of _______________ constitute machine-language programs.
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a) instructions
b) data
c) circuits
d) information
6. A _____________ clock (with hands) shows a more detailed time than a digital.
a) typic
b) formal
c) conventional
d) digital
7. _______________ are small computers specialized for mathematical computations.
a) Calculations
b) Calculators
c) Calibrators
d) Calibrations
8. An _______________ is an electronic devise to increase the strength of a current or voltage signal.
a) vibrator
b) rotation
c) amplifier
d) suspension
9. The case, the outside component which provides a fan and the ____________ supply, is used to both
cool the working parts inside and provide power to them.
a) power
b) circuit
c) electric
d) water
10. Most computers today have a hard disk which is the component most commonly used to provide
______________ storage of data.
a) permanent
b) temporary
c) fixed
d) volatile
11. A floppy drive is a low ______________ storage device which can be written to as easily as it is read.
a) size
b) component
c) capacity
d) capable
12. The floppy disk may be easily _____________ from a computer and used in another.
a) retrieved
b) recalled
c) reduced
d) removed
13. A CD-ROM is used to ____________ data from the hard drive so data is not lost if a hard drive breaks.
a) delete
b) eradicate
b) recall
d) back up
14. The sound card may be included as part of the motherboard or it may plug into a card __________ on
the motherboard.
a) slot
b) receiver
c) case
d) cartridge
15. The smallest element of a display surface on a screen is called …
a) byte
b) bit
c) pixel
d) line
16. Some operating systems permit hundreds or even thousands of _____________ users.
a) multiple
b) temporary
c) concurrent
d) quick
17. You have to ________________ an operating system into RAM.
a) boot`
b) run
c) perform
d) access
Use a form of the word in capitals to complete the sentences.
1.
2.
3.
4.
5.
A mouse is a device for ______________ the cursor and selecting items on the screen. (CONTROL)
Cordless mice are not physically ________________ at all. (CONNECT)
The operating system has even greater ___________________ and powers. (RESPONSIBLE)
Some software is designed to run under ______________ operating system. (SPECIFY)
A larger cluster size increases the likelihood that clusters will have ____________ space. (USE)
Use the words below to complete the text.
available - called – particular - popular – platform – determines – extend
Operating systems provide an operating _____________ on top of which other programs, _____________
application programs, can run. The application programs must be written to run on top of a ______________
operating system. Your choice of operating system, therefore, _______________ to a great __________ the
applications you can run. For PCs, the most ____________ operating systems are DOS, OS/2 and Windows,
but others are ________________ too, such as Linux etc.
Complete the text with the missing word
Removable hard disks __________ the type of disk system in which hard disks are enclosed in plastic
__________ metal cartridges so that ______________ can be removed like floppy disks. Removable disk
drives combine the best aspects of hard ____________ floppy disks. They are nearly __________ capacious
and fast as hard disks and have the portability of floppy disks. Their biggest drawback is _______________
they are relatively expensive.
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