Explain how laser beams work.
What will be an ideal response?
The laser is based on the principle that atoms in certain crystals and gases can be made to release a coherent, monochromatic (single-wavelength) energy when they are excited. The output is self-amplified in the laser because the excited atoms release their energy much more rapidly when stimulated by light emitted by neighboring atoms.
You might also like to view...
All of the following were characteristic of slaves in the mid-19th-cntury United States EXCEPT
A. slaves had no civil or political rights. B. slaves usually toiled from dusk to dawn in the fields. C. slaves had minimal protection from murder or unusually cruel punishment. D. slaves were forbidden to testify in court and their marriages were not legal. E. floggings were very uncommon and rare.
Explain the difference between direct and alternating current.
What will be an ideal response?
The temperature difference between the temperature of the cold water leaving the cooling tower and the wet bulb temperature of the air entering the tower is known as
A) Heat load B) Cooling range C) Approach D) Wet bulb depression
Which one of the following statements on PLC 5 module addressing is NOT true?
A) The PLC 5 chassis is configured by setting switches. B) A second colon (:) follows the rack number and the final two digits are the terminal numbers or input or output image table bit numbers. C) An I is used for inputs or an O for outputs. D) A colon (:) is used as a delimiter between the I or O and rack number.