OCR CT IT LO1 Recap

What is the binary equivalent of the decimal number 25?

• 11001

• 10011

• 10101

• 11101

Answer explanation

To convert the decimal number 25 to binary, divide by 2 and record the remainders. 25 ÷ 2 = 12 remainder 1, 12 ÷ 2 = 6 remainder 0, 6 ÷ 2 = 3 remainder 0, 3 ÷ 2 = 1 remainder 1, 1 ÷ 2 = 0 remainder 1. Reading the remainders from bottom to top gives 11001.

Convert the hexadecimal number “1F” into decimal.

• 15

• 31

• 29

• 34

Answer explanation

To convert hexadecimal '1F' to decimal, calculate: 1*16^1 + 15*16^0 = 16 + 15 = 31. Thus, the correct answer is 31.

Which of the following is the largest unit of storage?

• Bit

• Kilobyte

• Megabyte

• Gigabyte

• Terabyte

Which connectivity method is most commonly used in a wired LAN?

• Wi-Fi

• Ethernet

• Bluetooth

• Infrared

Answer explanation

Ethernet is the most commonly used connectivity method in wired LANs due to its reliability, speed, and widespread adoption. Other options like Wi-Fi and Bluetooth are primarily for wireless connections.

What is the main function of the CPU in a computer system?

• Store data permanently

• Process instructions

• Connect to peripheral devices

• Provide temporary memory

Answer explanation

The main function of the CPU is to process instructions. It executes commands from programs, performing calculations and managing data flow, which is essential for the computer's operation.

A computer is not turning on. What is the first step in troubleshooting?

• Replace the motherboard

• Check if the power cable is connected

• Install a new operating system

• Replace the RAM

Answer explanation

The first step in troubleshooting a computer that won't turn on is to check if the power cable is connected. This is a simple and common issue that can easily be overlooked before considering more complex repairs.

Which type of computer is best suited for real-time processing in an industrial setting?

• Desktop

• Mainframe

• Embedded system

• Laptop

Answer explanation

Embedded systems are specifically designed for real-time processing in industrial settings, offering dedicated resources and reliability, unlike desktops, mainframes, or laptops which are not optimized for such tasks.

Which of the following is an example of an output device?

• Keyboard

• Scanner

• Monitor

• Webcam

Answer explanation

A monitor is an output device that displays visual information from a computer. In contrast, a keyboard and scanner are input devices, while a webcam captures video input, not output.

Which device is both an input and an output device?

• Printer

• Touchscreen

• Mouse

• Projector

Answer explanation

A touchscreen serves as both an input and output device. It allows users to interact with the display by touching it (input) and also shows visual output, making it the correct choice among the options.

What is the primary purpose of RAM in a computer system?

• Connect to the internet

• Provide temporary storage

• Execute instructions

• Store data permanently

Answer explanation

The primary purpose of RAM (Random Access Memory) is to provide temporary storage for data and instructions that the CPU needs while performing tasks. This allows for quick access and processing, unlike permanent storage options.