technology Online Quiz - 1834

InnerTriangle is a package-private class (no access modifier before 'class'), meaning only classes within the geometry package can access it. Since base is a public field inside InnerTriangle, any class that can access InnerTriangle can also access base. Therefore, only classes in the geometry package can reference the variable base.

Inheritance in Java represents an 'is-a' relationship - a subclass 'is a' type of its superclass. Has-a relationships represent composition and are typically implemented using instance variables (e.g., a Car 'has an' Engine). Interfaces are not required for has-a relationships - you use composition directly with instance variables. Options A and D are both correct statements.

Line 19 attempts to call another constructor using 'Hello()' but this is invalid syntax. In Java, to chain constructors you must use 'this(...)' or 'super(...)' as the first statement. The statement 'Hello();' looks like a method call but there's no method named Hello(), so this code will not compile. Even if it were correct constructor chaining, line 14 would throw NullPointerException because title is null when += is attempted.

Static members are accessed based on the reference type, not the actual object type. Base.FOO prints 'foo' (accessing Base's static variable). Sub.FOO prints 'bar' (accessing Sub's static variable). b.FOO prints 'foo' because b is declared as Base type. s.FOO prints 'bar' because s is declared as Sub type. ((Base)s).FOO prints 'foo' because the cast changes the reference type to Base. The result is 'foobarfoobarfoo'. Static members are not polymorphic - they depend on compile-time type.

In traditional Ethernet (10BASE5 and 10BASE2), the maximum number of repeaters allowed in a path between any two stations was 4, creating 5 segments. This is known as the 5-4-3 rule: 5 segments, 4 repeaters, with only 3 segments populated. This rule was designed to limit collision domain timing and ensure proper collision detection. The 4 repeaters (or 5 segments) limit was a fundamental constraint in classic coaxial Ethernet networks.

RPC (Remote Procedure Call) operates at the Session layer (Layer 5) of the OSI model. The Session layer is responsible for establishing, managing, and terminating communication sessions between applications. RPC provides a mechanism for a client to invoke a procedure on a remote server as if it were local, which is a session management function. While RPC functionality spans layers, its session management and communication control aspects align with the Session layer's responsibilities.

FTP (File Transfer Protocol) and Telnet are Application layer (Layer 7) protocols in the OSI model. The Application layer provides network services directly to user applications. FTP handles file transfers between client and server, while Telnet provides remote terminal access. Both protocols operate at the top layer of the OSI model, interacting directly with end-user applications and providing network services at the application level.

ARP (Address Resolution Protocol) resolves IP addresses to MAC addresses in local networks. When a device needs to send data to an IP address, it broadcasts an ARP request to find the corresponding MAC address. RARP does the reverse (MAC to IP), NAT translates addresses for routing, and DARP is not a standard protocol.

TCP is connection-oriented and establishes virtual circuits through three-way handshaking, ensuring reliable delivery. UDP is connectionless and sends datagrams without establishing virtual circuits, prioritizing speed over reliability. Options B, C, and D incorrectly state that UDP provides virtual circuits or that neither protocol uses them.

BOOTP (Bootstrap Protocol) operates at the Application Layer (Layer 7) of the OSI model, similar to DHCP. It allows diskless workstations to obtain IP addresses and boot configuration. The Network Layer handles IP routing, Session Layer manages connections, and Presentation Layer handles data translation/encryption.

Bluetooth uses Synchronous Connection-Oriented (SCO) links for voice transmission because they provide guaranteed bandwidth and low latency required for real-time voice communication. Asynchronous Connectionless (ACL) links are for data, and radio waves/UV are transmission media, not Bluetooth link types.

Bluetooth Class 2 devices have a standard range of approximately 10 meters (about 33 feet) without using cables or additional equipment. This is the most common range for consumer Bluetooth devices like headsets, speakers, and phones. Range of 1 meter is too short, 100+ meters requires Class 1 devices with amplifiers.

Bluetooth uses frequency-hopping spread spectrum (FHSS) to minimize interference. It hops 1600 times per second across 79 channels in the 2.4 GHz ISM band. This rapid hopping makes the connection robust against interference. Option C (79 per second) confuses the number of channels with hop rate, while A and B use minutes instead of seconds.

A Bluetooth network formed when devices connect is called a piconet. One device acts as master and up to 7 others as slaves. PAN (Personal Area Network) is a broader category that includes piconets. LAN, WAN are larger scale networks. The question specifically asks for the Bluetooth network name.

Bluetooth operates in the 2.4 GHz ISM band using radio waves. It does not use infrared (line-of-sight limitation) or UV rays (harmful, not used for short-range communication). Radio waves allow non-line-of-sight communication through walls and obstacles within the 10-100 meter range.

In a Bluetooth piconet, one master device can actively connect to up to 7 slave devices simultaneously. The total piconet size is 8 devices (1 master + 7 slaves). Additional devices can be parked but not actively communicating. Option C (8) counts the master, which is not 'connected to' the master.

Bluetooth prevents interference through Frequency-Hopping Spread Spectrum (FHSS). Devices hop 1600 times/second across 79 channels, so collisions are brief and retransmission handles them. L2CAP is a protocol layer above. 'Air sniffing' is not a Bluetooth term. Note: option has typo 'Hoping' instead of 'Hopping'.

Bluetooth operates in the 2.4-2.48 GHz ISM (Industrial, Scientific, Medical) band. 2.45 GHz is the center frequency commonly cited. Options in MHz (megahertz) would be 1000x too small. BHz is not a standard unit. Hz alone is far too low. This is the same band used by WiFi and microwaves.