The built-in memory of a computer typically refers to RAM (Random Access Memory). RAM is a type of volatile memory that the computer uses to temporarily store data that is actively being used or processed. It provides fast access to the data the computer needs to perform tasks, and its content is erased when the computer is powered off.

An output device that is used for TV-like displays and shows the output on the screen is indeed called a monitor. It is also commonly referred to as a visual display unit (VDU). Monitors and VDUs are used to display visual information from computers and other electronic devices, allowing users to view text, images, videos, and other graphical content. They come in various types, including CRT (Cathode Ray Tube), LCD (Liquid Crystal Display), LED (Light Emitting Diode), and OLED (Organic Light Emitting Diode) monitors.

1. The horizontal lines displayed in the plot area of a chart in MS Excel 2010 are called gridlines.

2. Types of Grid Lines in MS Excel 2010 –

- Main grid lines: These show the key values of the data ranges. They have usually displayed every 5 or 10 values.

Secondary grid lines: These show the intervals between data ranges. They usually appear after every 1 or 2 values.

The "@" symbol is used to separate the username of an email address from the domain name of the Internet Service Provider (ISP) or email service provider. For example, in the email address "username@example.com," "username" is the username of the email account, and "example.com" is the domain name of the email service provider, separated by the "@" symbol.

A plotter is an output device that prints vector graphics on hard copy. Unlike printers, which are designed for raster graphics and text, plotters are specialized devices used to produce high-quality drawings, diagrams, and other vector-based illustrations. Plotters use pens or other drawing tools to create precise lines and shapes on paper, making them particularly useful for applications that require detailed and accurate graphical output, such as architectural and engineering designs.

 In the context of computer viruses or malware, a time bomb is a type of malicious code that is programmed to execute a harmful action at a specific date and time or after a certain period has elapsed. This delayed activation makes it challenging to detect and prevent the attack until it's too late.