21. A Hall effect switch is usually used to:

A.,  measure voltage
B. measure temperature
C. sense a vacuum
D. sense the presence of a magnetic object.
E. None of the above

22. The hardware device Jhat acts as both a switching and connecting unit is called a(n):

A. concentrator
B. RS-232C port
C. multiplexer
D. communications processor
E. None of the above

23. The addition of _____ can reduce processing time.

A. A buffer
B. An EPROM
C. A converter
D. A co-processor
E. None of the above

24. Which of the following method is used the results of a design analysis as a base for redesign decisions?

A. The iterative design method
B. The direct method
C. The design selection method
D. All of the above
E. None of the above

25. What kind of capability is required if one plans to interface with a plotter or printer?

A. A graphics cable
B. RGB monitor
C. A graphics board
D. A co-processor
E. None of the above