Java Programming and Computer Technology

A Bluetooth piconet consists of one master device and up to 7 active slave devices, totaling 8 devices. This is the Bluetooth standard specification for simultaneous active connections in a piconet network.

Intel 4004 was the first commercially available microprocessor (CPU on one chip), released in 1971. It was a 4-bit processor. Intel 8085 came much later (1977), and Intel 8086 (1978). Intel 3003 was not a CPU chip.

Mapped network drives create a persistent connection that caches directory information and provides faster access through Windows Explorer. My Network Places browses the network each time, which is slower as it doesn't maintain the same cached connection.

The network layer (Layer 3 in OSI model) is responsible for routing packets from the source host to the destination host across multiple networks using logical addressing (IP addresses) and routing protocols.

To solve this question, the user needs to know the definition of a router and understand the concept of multiple protocols.

A router is a networking device that forwards data packets between computer networks. It uses headers and forwarding tables to determine the best path for forwarding the packets.

Multiple protocols refer to the ability of a router to handle different network layer protocols simultaneously.

Now, let's go through each option and explain why it is right or wrong:

A. Ethernet: This option is incorrect. Ethernet is a family of computer networking technologies commonly used in local area networks (LANs). Although routers may use Ethernet to connect to devices, Ethernet is not a term used to describe routers.

B. Internet: This option is incorrect. The Internet is a global network of networks that use the Internet protocol suite (TCP/IP) to link devices worldwide. Although routers are used to forward data packets on the Internet, the term Internet is not used to describe routers.

C. Multiprotocol: This option is correct. A router that can handle multiple protocols is called a multiprotocol router. It is designed to handle different network layer protocols simultaneously, such as IP, IPX, and AppleTalk.

D. None of the above: This option is incorrect. The correct answer is C, as explained above.

The answer is: C

Piggybacking is a technique where acknowledgments are temporarily delayed and attached to the next outgoing data frame, improving efficiency by reducing the number of separate acknowledgment frames transmitted over the network.

The data link layer (Layer 2) is responsible for encapsulating packets from the network layer into frames for transmission over the physical medium, adding headers and trailers for addressing, error detection, and flow control.

The data link layer (OSI Layer 2) is responsible for encapsulating packets from the network layer into frames for transmission over the physical medium. This is a fundamental networking concept - framing adds layer 2 headers and trailers for addressing and error detection.

Unidirectional protocols allow data flow in only one direction (simplex communication), while sliding window protocols support bidirectional flow control and reliability. Sliding window is a technique for managing acknowledgments and retransmissions in either direction.

The data link layer has three core functions: (1) providing a service interface to the network layer, (2) handling transmission errors via checksums/CRC and ARQ mechanisms, and (3) flow control to prevent fast senders from overwhelming slow receivers. All listed options are correct.

SCSI (pronounced 'scuzzy') stands for Small Computer System Interface. It's a standard interface for connecting peripheral devices like hard drives, scanners, and optical drives to computers. The other options are invented expansions.

Protected visibility in Java spans two scopes: (1) all classes within the same package (like default access), plus (2) subclasses in other packages. This makes protected broader than package-private but narrower than public.

Statement 1 is true - abstract classes cannot be instantiated directly. Statement 2 is true - constructors are never abstract; they're concrete by definition. Statement 3 is false - a subclass can remain abstract and not implement all abstract methods. Statement 4 is false - static methods belong to the class, not instances, so they cannot be abstract.

Java access control keywords are: default (package-private), protected, and public. Abstract, interface are not access modifiers - they define class/method types. The correct set is abstract (B), protected (C), and public (E).

Java keywords are reserved words with special meaning. 'switch' and 'default' are valid keywords. 'integer' is not a keyword (int is the primitive type). 'boolean' is a keyword (primitive type). 'object' is not a keyword (Object is a class).

To solve this question, the user needs to have knowledge about the initial version of Java and the keywords that were reserved but not used. The user must then identify which options list the correct keywords.

The correct answer is:

D. (B),(C) & (D)

Explanation:

In the initial version of Java, the keywords "const" and "goto" were reserved but not used. The keyword "inner" was not reserved at all in the initial version of Java. The other options, "union", "boolean", and "synchronized" were not keywords in the initial version of Java.

Therefore, options (A) and (C) are incorrect as they include options that were not reserved in the initial version of Java. Option (B) is incorrect as "boolean" was not a reserved keyword in the initial version of Java. Option (D), on the other hand, correctly lists all the keywords that were reserved but not used in the initial version of Java, which are "const", "goto", and "inner".

The Answer is: D. (B),(C) & (D)

In Java, NULL (should be null), extended (should be extends), and string (String is a class) are not keywords. 'implements' and 'protected' are valid Java keywords. Option B correctly identifies the three items that are not keywords.