CompTIA认证考试PD0-001单项选择题每日一练(2019.01.18)

单项选择题
Which of the following devices can route electrical signals only when activated by an external control signal？（）
A.Solenoid
B.Relay
C.Clutch
D.Capacitor
单项选择题
When arriving at the customers location， two different users describe the problem， and from their description it seems to be two separate problems. Which of the following is an appropriate step to take？（）
A.Ignore both of them and decide what the real problem is.
B.Set up a separate call for each problem.
C.Have them duplicate the problem at the device.
D.Ask a third person and see if the problem is the same thing.
单项选择题
Which of the following failed components would be responsible for the fuser unit not heating properly？（）
A.Halogen lamps
B.Ball bearing
C.Hot roller
D.Pressure roller
单项选择题
Which of the following items can be used as a discharge lamp？（）
A.Halogen lamp
B.Light Emitting Diodes （LED）
C.Fuser lamp
D.Cleaning roller
单项选择题
Which of the following is a reason black toner is used in color printers？（）
A.It decreases the print speed in color laser printers.
B.It prevents moir patterns when printing color photographs.
C.It reduces the cost per page when printing gray scale documents.
D.It makes the color toner resistant to smudging when wet.