Answer: D) All the above Explanation: In MS-Word, the Ruler function helps align the text, graphic, tables or other elements in your document.

Answer: A) print files on paper Explanation: A report generator is a computer program whose purpose is to take data from a source such as a database, XML stream or a spreadsheet, and use it to produce a document in a format which satisfies a particular human readership.   Hence, A report generator is used to print files on paper.

Answer: D) All the above Explanation:

Answer: C) Queue Explanation: A data structure is a specialized format for organizing and storing data. General data structure types include the array, the file, the record, the table, the tree, and so on. Any data structure is designed to organize data to suit a specific purpose so that it can be accessed and worked with in appropriate ways.   Linear data structure: A linear data structure traverses the data elements sequentially, in which only one data element can directly be reached. Ex: Arrays, Linked Lists, Stack, Queue, Any type of List all are linear.   Trees like Binary Tree, B Tree or B+ Tree are examples of non linear data structure.

Answer: A) Dn = log 2 (n+1) Explanation: A complete binary tree is a binary tree where all the levels have maximum number of nodes except possibly the last level.   The depth of complete binary tree of n nodes will be Dn=log 2 (n+1) where Dn is the height or depth of the tree and n is the number of nodes.

Answer: A) 256 kb to 640 kb Explanation: Size of the primary memory of a PC ranges between 256 KB to 640 KB.

Answer: A) Laser Explanation: Compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony and released in 1982.  These are actually made to replace floppy disks that were used to store files and programs from the computer.   The format was originally developed to store and play only sound recordings but was later adapted for storage of data (CD-ROM).   These CD's uses Laser technology.

Answer: D) Screen Explanation: A touch screen is the only device which works as both an input and an output device among the given options. You view the options available to you on the screen (output) and you then use your finger to touch the option that you have chosen (input).   Hence, Screen is not purely output device.