Why are vacuum tubes also called valves?

A. Because they can amplify the weak signals and make them strong

B. Because they can stop or allow the flow of current

C. Both of above

D. None of above

Please do not use chat terms. Example: avoid using "grt" instead of "great".

You can do it
  1. Which of the following programming language started from second generation?
  2. WAN is a most used abbreviation in Networking, what is its full form?
  3. Which of the following require large computers memory?
  4. MSI is the abbreviation of
  5. A program that performs a useful task while simultaneously allowing destructive acts is
  6. The typical computer criminal is a(n):
  7. What is the first stage in software development?
  8. You use a(n) ________, such as a keyboard or mouse, to input information
  9. RAM can be treated as the ________ for the computer's processor
  10. A factor which would strongly influence a business person to adopt a computer is its
  11. Integrated Circuits (Ics) are related to which generation of computers?
  12. Which of the following is the most powerful computers?
  13. The programs which are as permanent as hardware and stored in ROM is known as
  14. Where as a computer mouse moves over the table surface, the trackball is
  15. ________is a combination of hardware and software that facilitates the sharing of information between…
  16. Which of the following is NOT one of the four major data processing functions of a computer?
  17. Which of the following storage devices can store maximum amount of data?
  18. ________printer is the cheapest in terms of price and operating cost
  19. Which of the following controls the process of interaction between the user and the operating system?
  20. CD-ROM is a
  21. What was the expected feature of fifth generation computers when Japan started FGCS?
  22. Which of the following produces the best quality graphics reproduction?
  23. Who invented the high level language C?
  24. Magnetic disks are the most popular medium for
  25. Which American computer company is called Big Blue?
  26. One millisecond is
  27. Which electronic component was made out of semiconductor material?
  28. which of the following is problem oriented language?
  29. A Pixel is
  30. Computer is free from tiresome and boardroom. We call it