# HSSC Computer Notes – 1

1. Which unit is responsible
for converting the data received from the user into computer understandable
format?
a) Memory Unit
b) Arithmetic & Logic Unit
c) Input Unit
d) Output Unit
Explanation: The Input Unit converts the data,
which the user enters into a language which the computer understands, i.e. it
converts the data into binary format. The Output Unit is responsible for giving
the results in user understandable format. The Storage Unit is responsible for
storing the data after immediate results of processing whereas; the ALU is
responsible for various arithmetic and bitwise operations.

2. The only language which
the computer understands is ______________
a) Assembly Language
b) Binary Language
c) BASIC
d) C Language
Explanation: The Computer
understands only binary language which is written in the form of 0s & 1s. A
computer can understand assembly language but an assembler is required which
converts the assembly language to binary language. Similarly, for understanding
high level languages, compilers/interpreters are required.
Contents

## Computer System Parts

3. The smallest unit of data in computer is
________________
a) Byte
b) Nibble
c) Bit
d) KB
Explanation: A bit is
defined as the smallest unit of data in a computer system. It is used as a
short form of Binary Digit. A bit can have only two values 0 or 1. A nibble
comprises of 4 bits, a byte is a collection of 8 bits whereas KB (Kilobyte) is
equal to 1024 bytes.
4. One nibble is equivalent to how many bits?
a) 2
b) 4
c) 8
d) 1

Explanation: A nibble is
defined as a unit of data which comprises of 4 binary digits or half of 8-bit
byte. Therefore, 1 nibble = 4 bits. A bit is the smallest unit of data in a
computer system. A byte = 8 bits, therefore, half of a byte=4 bits=a nibble.

5. Which of the following describes the
correct format of an input instruction?
a) IN 82
b) INPUT 82
c) INP 82
d) 82 INP

Explanation:
The input/output instructions are used to transfer information between external
peripherals and the CPU. The correct format of an input instruction is: IN
8-bit port address. Here, IN 82 is the correct option, where 82 is the
designated port address. All the other options are invalid.