___ are signal converters, which converts a physical variable (temp., position, pressure, etc.) into a different, more easily evaluated variable (usually an electrical signal)

Sensors provide sensing and measurement of the process and variable in manufacturing; they are always the first device in the whole automation system; they provide feedback in closed-loop systems.

• True

• False

Sensors which detect movement by means of contactless sensing (magnetic, optical, inductive or capacitive)

These converts physical quantity into a continuous analogue signal in which signal’s amplitude (current, voltage, resistance) or frequency or pulse width (PWM) tells the extent of the physical quantity being measured.

These converts physical quantity into a continuous analogue signal in which signal’s amplitude (current, voltage, resistance) or frequency or pulse width (PWM) tells the extent of the physical quantity being measured.

In a 2-wire DC/AC Technology the load is connected in series with the sensor and the supply.

• True

• False

Possess antivalent switching function (possess both NO and NC in just one device)

Magnetic Field Lines always run from the north pole to the south pole; Both poles never occur individually.

• True

• False

___ are magnetized by applying strong magnetic field to them so as to retain the magnetic field in them

__ are temporarily magnetized by applying current to its conducting wire; an iron core is placed to further intensify or align the generated magnetic field