plc Controllers and Actuators

Multiple Choice Questions UNIT III

1. In process process control control the basic basic objecti objective ve is to _______ _________ __ the value value of some quanti quantity ty.. a] Regulate b]Control c]Both a&b . ________ _________is _is a comple! comple! assembl assembly y of phenomen phenomenaa that relate relate to some some manufact manufacturing uring sequen sequence. ce. a] Controlle" variable b] #rocess c]manipulate" variable $. ________ __________ __ refers to the the time for the processco processcontro ntroll loop to ma%e necessary necessary a"just a"justment mentss to the final control element a] Control lag b] #rocess c]manipulate" variable . ________ ________ is the elapse" elapse" time time bet'een the the instant instant "eviation "eviation occurs occurs an" 'hen the the corrective corrective action action first occurs. a] Controlle" variable b] #rocess c] (ea" time. ). *n+*ff *n+*ff is is the typ typee of ______ _________ ______ ___,o" ,o"e. e. a] (iscontinuous controller b] on off control

c]Continuous Controller  

-. he t'o positio position n control control mo"e is best a"apte" a"apte" to large large scale system system 'ith relativ relatively ely slo' proces processs rates. a] small b] large c]me"ium /. ________ ____________ _________ _______con __control trol mo"e mo"e is use" in an attempt attempt to re"uce the the cycling cycling behavior behavior 0 overshoot0 un"ershoot inherent in the t'o position mo"e. a] Continuous b] on off control c] multiposition . 2 controller operates 'ith 'ith __________ __________ 'hen 'hen an increasing value of the controlle" controlle" variable variable causes causes an increasing value of the controller output. a] (irect action b] reverse 2ction c]manipulate" variable 3. 2 control controller ler operates operates 'ith ________ ____________ ____ 'hen an increasin increasing g value of the controlle" controlle" variable variable causes an "ecrease in value of the controller output. a] (irect action b] on off control c]reverse action 14. floating control the the specific output of of the controller is not uniquely uniquely "etermine" "etermine" by the error. 2] ,ultiposition Control b] on off control c]floating control