1. Identify whether the following sentences are true or false. Use the model:

1. Student A: 1. In most hard disk drives the platters cannot be removed. _v Student B: Yes, That is true. For that reason they are called fixed disc drives.

2. S. A: A hard disk drive contains rigid, disk-shaped platters made ₀ copper. — S. B: No, that is false. They are made of aluminium or glass.

1. Winchester drives are considered synonymous with hard disk.

2. A sector is a concentric ring of information, which is divided into individual tracks.

3. A hard disk drive normally has two head per platter side.

4. The nearer to the circumference of the magnetic disk, the lower the track recording density can be made.

5. The result of a head crash may lead to a totally trashed drive.

6. The basic principle of physics states that as electric current flows through a conductor, a magnetic field is generated inside the conductor.

7. The two-way operation of electromagnetism makes it possible only to record data on a disk.

2. Complete the following sentences using words and expressions given below.

1. A hard drive uses ... heads that move over the disks and store data in tracks and sectors.

2. Disk drives have become a standard data storage component of modern computer systems due to ... physical size.

3. Hard disks usually have ... platters, each with two sides on which data can be stored.

4. When the direction of the flow of electric current is reversed, the magnetic field's ... also is reversed.

5. The term Winchester drive has no technical or scientific ... .

6. A car alternator operates by rotating electromagnets past coils of wire conductors in which large amounts of electrical current can be ....

1.14. Read and translate the text

Virtual reality

Virtual reality (VR) is computer-simulated reality. Virtual reality is a fast-growing area of artificial intelligence that had its origin in efforts to build more natural, realistic, multisensory human/computer interfaces. So virtual reality relies on multisensory input-output devices such as a tracking headset with video goggles and stereo earphones, a data glove or jumpsuit with fiber-optic sensors that track your body movements, and a walker that monitors the movement of your feet. Then you can experience computer-simulated "virtual words" three-dimensionally through sight, sound and touch. Thus, virtual reality is also called telepresence. For example, you can enter a computer-generated world, look around and observe its contents, pick up and move objects and move around in it at will. Thus, virtual reality allows you to interact with computer-simulated objects, entities and environments as if they actually exist.

Current application of virtual reality are wide ranging and include computer-aided design (CAD), medical diagnostics and treatment, scientific experimentation in many physical and biological sciences, flight simulation for training pilots and astronauts, product demonstrations, employee training and entertainment, especially 3-D video arcade games. CAD is the most widely used industrial VR application. It enables architects and other designers to design and test electronic 3-D models of products and structures by entering the models themselves and examining, touching and manipulating sections and parts from all angels.

VR designers are creating everything from virtual weather patterns and virtual wind tunnels to virtual cities and virtual securities markets. For example, by converting stock market and other financial data into three-dimensional graphic form, securities analysts can use VR systems to more rapidly observe and identify trends and exceptions in financial performance. Also promising are applications in information technology itself. This includes the development of 3-D models of telecommunications networks and databases.

VR becomes telepresence when users that can be anywhere in the world use VR systems to work alone or together at a remote site. Typically, this involves using a VR system to enhance the sight and touch of a human who is remotely manipulating equipment to accomplish a task. Examples range from virtual surgery, where surgeon and patient may be on either side of the globe, to the remote use of equipment in hazardous environments such as chemical plants or nuclear reactors.

VR Limitations. The use of virtual reality seems limited only by the performance and cost of its technology. For example, some VR users develop cybersickness, such as eyestrain and motion sickness, from performance problems in the realism of VR systems. The cost of a virtual reality system is another limitation. A VR system consisting of a headset with goggles and headphones, a fiber-optic data glove, motion-sensing devices and a powerful engineering workstation with top-quality 3-D modelling software can exceed $ 50,000. If you want less cumbersome devices, more realistic displays and more natural sense of motion in your VR world, costs can escalate into several hundred thousand dollars. CAVEs (cave automatic virtual environments), virtual rooms that immerse you in a virtual reality experience, cost several million dollars to set up.

For example, the Market Risks Department of Morgan Stanly & Co. uses Discovery virtual reality software by Visible Decisions to model risks of financial investments in varying market conditions. Discovery displays three-dimensional results using powerful Silicon Graphics workstations.