A relay is a device that ________
A) isolates the actuating signal from the control signal
B) uses an electromagnet to open and close contacts
C) has a coil to actuate some contacts that control other circuits
D) all of these
D
You might also like to view...
____ frames are a three-dimensional truss system that can achieve very long spans.
A. Open-web B. Space C. Pratt D. Howe
One of two machines, alpha and beta, is to be purchased to provide for a new production operation in a factory. Machine alpha costs $10 000 and machine beta, $15 000. However, machine beta will result in an annual savings in operating costs of $800 over machine alpha. Which machine would you recommend purchasing and why, if each has a useful life of 10 years and money is worth 6 percent? Assume that both machines will be worthless at the end of 10 years. What value of annual savings of machine beta over machine alpha would result in each being equally desirable?
What will be an ideal response?
Emphasis creates attention on one feature. Name two features of emphasis
What will be an ideal response?
In desalting groundwater that contains a significant amount of sulfates, the concentrate that is generated during the desalting process can sometimes be tough on equipment, so the equipment’s useful life is uncertain. For a treatment train that has an initial cost of $90,000 and an estimated operating cost (OC) between $15,000 and $20,000 per month, use a spreadsheet to determine how many months the equipment must last to recover the investment at i = 0.5% per month at each OC value? Assume the income from the sale of calcium sulfate is $22,000 per month. (Note: Solve using increments of $1000 OC per month.)
What will be an ideal response?