science & technology Online Quiz - 7

Standard SMS messages are limited to 160 characters. Concatenated SMS (also called long SMS or segmented SMS) breaks longer messages into multiple 160-character segments that are reassembled by the recipient's phone, appearing as one continuous message. VMS is voicemail, EMS is an enhanced messaging service (rarely used now), and MMS is for multimedia content.

An SMS gateway acts as a bridge between different networks and media, converting SMS messages to mobile network traffic and vice versa. It enables sending/receiving SMS without a mobile phone - through email, web applications, or APIs. VMS is voicemail, EMS is enhanced messaging (largely obsolete), and 'Fast SMS' is not a standard term.

A Direct-To-Mobile gateway has a built-in GSM modem and SIM card, allowing it to send SMS directly to mobile handsets without going through a carrier's SMSC. This is useful for bulk messaging. Direct-To-SMSC gateways connect to the carrier's SMSC via TCP/IP or other protocols.

SMS services encompass various communication methods. Notification services send automated alerts (banking, security, etc.). E-mail interworking allows SMS-to-email and vice versa. Paging interworking bridges SMS and legacy pager networks. All three are standard SMS capabilities offered by carriers and gateways.

MT-SM (Mobile Terminated - Short Message) is sent TO a handset, so delivery confirmation goes back to the SMSC (which initiated it). MO-SM (Mobile Originated) is sent FROM a handset, so its status report goes back to the handset as confirmation. This is fundamental to SMS flow control.

A Direct-To-SMSC gateway connects directly to the mobile carrier's SMSC (Short Message Service Center) via protocols like SMPP, UCP/EMI, or CIMD. It doesn't have its own GSM modem. This enables applications, email systems, and web services to send SMS by routing through the carrier's infrastructure. Direct-To-Mobile gateways have built-in GSM modems.

H2S is a gas at room temperature due to weak intermolecular forces, while H2O is a liquid because of strong hydrogen bonding between water molecules. This difference occurs because sulfur is larger and less electronegative than oxygen.

Prismatic sulfur (also known as monoclinic sulfur) forms needle-shaped crystals when it crystallizes. This is one of the crystalline allotropes of sulfur.

Gold paint is traditionally made from copper powder suspended in a medium, as copper gives a gold-like metallic appearance when finely ground and polished. Pure gold would be prohibitively expensive for paint.

Hydrogen sulfide (H2S) acts as a reducing agent because it can donate electrons (sulfur is oxidized from -2 to higher oxidation states). Sulfur dioxide is actually an oxidizing agent in most reactions.

Concentrated sulfuric acid (H2SO4) is a powerful dehydrating agent because it has a high affinity for water, often removing hydrogen and oxygen atoms from compounds to form water.

Sulfur dioxide (SO2) acts as a bleaching agent through reduction - it removes color by breaking down conjugated double bonds in colored compounds. Sulfuric acid is not a bleaching agent, and hydrogen sulfide is primarily a reducing agent used in different contexts.

The claimed answer B (eXtensible Markup Language) is correct. XML stands for eXtensible Markup Language, named because it allows users to define their own custom markup tags (extensibility). Options A, C, and D are incorrect as they are made-up expansions that don't represent the actual acronym.

The claimed answer B () is correct. The XML declaration must use a question mark at both the start and end, not a slash like regular tags. Option A incorrectly uses and />, Option C incorrectly uses /> instead of ?>, and Option D is incorrect since B is valid.

The claimed answer A (Yes) is correct. XML has strict, consistent rules (all tags must be closed, properly nested, case-sensitive), making it more predictable and easier for parsers to process than HTML, which has many exceptions and inconsistent tag-handling rules. Options B, C, and D are incorrect.

The claimed answer B (All XML elements must have a closing tag) is correct. XML requires every opening tag to have a corresponding closing tag (or be self-closed with />). Option C is incorrect because XML is case-sensitive but doesn't require lowercase. Option D is incorrect because DTD is optional in XML.

The claimed answer C (non-validating and validating) is correct. XML parsers are classified into two main types: non-validating parsers (check only for well-formedness) and validating parsers (check both well-formedness and adherence to a DTD or schema). Options A, B, and D are incorrect as they don't represent actual parser classifications.

The claimed answer D is correct. A well-formed XML document must have exactly one root element that contains all other elements in a hierarchical tree structure. Options A and B are incomplete (single element requirement is insufficient). Option C is partially correct but doesn't emphasize the critical root element requirement.

XML comments are enclosed between . This syntax is inherited from SGML and is the standard way to add comments that should be ignored by XML parsers. Options B, C, and D use incorrect characters or sequences.