Computer Science Principles Answer Key

1. 2. Which of the following best describes a challenge involved in using a parallel computing solution? (A) A parallel computing solution may not be appropriate for an algorithm in which each step requires the output from the preceding step. (B) A parallel computing solution may not be appropriate for an algorithm in which the same formula is applied to many numeric data elements. (C) A parallel computing solution may not be appropriate for an algorithm that can be easily broken down into small independent tasks. (D) A parallel computing solution may not be appropriate for an algorithm that searches for occurrences of a key word in a large number of documents. Which of the following statements correctly explain how the Internet is able to facilitate communication at a large scale? I. A central monitoring computer is used to track and maintain the connections of the Internet. II. Data is routed between points in multiple ways so that if a connection fails, the data can be rerouted around the inoperative connections. III. Protocols for packets and routing are used so that computers from different manufacturers can communicate in a standard way. (A) I and II only (B) I and III only (C) II and III only (D) I, II, and III 3. Directions: The question or incomplete statement below is followed by four suggested answers or completions. Select the one that is best in each case. Which of the following explains a benefit of using open standards and protocols for Internet communication? (A) Open standards and protocols allow different manufacturers and developers to build hardware and software that can communicate with hardware and software on the rest of the network. (B) Open standards and protocols provide ways for users to eliminate the latency of messages they send on the Internet. (C) Open standards and protocols allow users to freely share or reuse material found on the Internet for noncommercial purposes. (D) Open standards and protocols prevent developers from releasing software that contains errors. 4. Which of the following is a primary benefit of making a computing system fault-tolerant? (A) If one component of the system fails, users of the system can often still access it. (B) If one component of the system is hacked, no information will be stolen. (C) If the system becomes too expensive, making it fault-tolerant will save money. (D) If the system cannot operate efficiently, making it fault-tolerant will speed up its operation. 5. The transmission control protocol (TCP) and Internet protocol (IP) are used in Internet communication. Which of the following best describes the purpose of these protocols? (A) To ensure that communications between devices on the Internet are above a minimum transmission speed (B) To ensure that private data is inaccessible to unauthorized devices on the Internet (C) To establish a common standard for sending messages between devices on the Internet (D) To validate the ownership of encryption keys used in Internet communication 6. The figure below represents a network of physically linked devices, labeled A through H. A line between two devices indicates a connection. Devices can communicate only through the connections shown. What is the minimum number of connections that would need to be removed from the network in order for device A to not be able to communicate with device F? (A) 2 (B) 3 (C) 4 (D) 5 7. Directions: For the question or incomplete statement below, two of the suggested answers are correct. For this question, you must select both correct choices to earn credit. No partial credit will be earned if only one correct choice is selected. Select the two that are best in each case. Researchers have developed a simulation of packets traveling between server computers and client computers in a network. Of the following, which two outcomes are most likely to be results of the simulation? Select two answers. A Better understanding of the effect of temporarily unavailable network connections B Better understanding of the effect of using hexadecimal representations for binary data C Better understanding of the impact of access to public data in identifying solutions to problems D Better understanding of the impact of increased connection speeds for frequently visited servers 8. Which of the following network devices is responsible for finding and changing the paths of data packets as needed? (A) Network firewall (B) Network interface card (C) Network repeater (D) Network router 9. Two people with access to the same bank account made two separate withdrawals from the account. They made the withdrawals at the same time but at two separate bank branches. At the time of the withdrawals, the account had $400. Both people checked the account balance before making their withdrawal and saw that it was $400. One person withdrew $200, and the other person withdrew $250. Both transactions were successful. Later, the two people each received an e-mail from the bank saying that the account was overdrawn. Which of the following best describes the error in the bank software that caused this problem? (A) The bank software erroneously allowed multiple tasks to be running at the same time. (B) The bank software failed to correctly authenticate and authorize the users accessing the account. (C) The bank software erroneously allowed two different processes to access shared data at the same time. (D) The bank software erroneously used virtual memory instead of physical memory to store the data. 10. Which of the following best describes how network load and latency change as more devices are connected to the Internet in a home network? (A) Both the network load and the latency decrease. (B) The network load decreases and the latency increases. (C) The network load increases and the latency decreases. (D) Both the network load and the latency increase. 11. Which of the following features would be the most beneficial for Deaf people who are accessing a Web site? (A) Captions for video media (B) Limited use of color contrast and sound to convey meaning (C) Alternate text for all images (D) An advanced speech synthesizer 12. Which of the following is an example of the Internet of Things (IoT) ? (A) A driver uses a remote car starter to warm up the car when it is cold outside. (B) A coffeemaker in the kitchen turns on when an alarm clock uses the Internet to send it a message. (C) A computer automatically runs a daily scan to look for viruses. (D) A customer receives an automatically generated e-mail via the Internet for a special discount at a local shop. 13. Which of the following is a primary difference between encoding and encryption? (A) Encoding involves binary digits and encryption does not. (B) Encoding transforms data and encryption does not. (C) Encryption is used in online transactions and encoding is not. (D) Encryption is used to restrict access and encoding is not. 14. Which of the following is a true statement about data transmitted over the Internet? 1. 2. 3. 4. All data traveling over the Internet is binary. Packets are received in the same order that they are sent. The Internet is built on redundant connections. The Internet Protocol is designed to be inexpensive to allow access to smaller websites. (A) 2 & 4 only (B) 1 & 3 only (C) 1, 2, & 3 (D) 1, 2, 3 & 4 15. Which of the following is a benefit of using open standards and protocols for Internet communication? Select TWO answers. A Open standards increase adoption, allowing for reliable end-to-end architecture. B Increase in bandwidth for wireless connections. C Decrease in the digital divide. D No interpretations in communications are required between all types of hardware and all kinds of operating systems.