Question: An electricomechanical relay uses electromagnetism to operate contacts

Answer: True

Question: A normally closed (NC) relay contact is closed when current flows through the coil.

Answer: False

Question: A relay usually will have only one coil but a number of different contacts.

Answer: True

Question: In general, control relay contacts are deigned to handle higher currents than contactors.

Answer: False

Question: A selector switch is rotated to open and close contacts.

Answer: True

Question: Proximity switches usually sense the presence or absence of a target by means of physical contact.

Answer: False

Question: An inductive proximity sensor is actuated by conductive and non conductive materials.

Answer: False

Question: A through-beam photoelectric sensor is used to detect the light beam reflected from a target.

Answer: False

Question: Weight strain gauges operate by detecting small changes in temperature.

Answer: False

Question: Fiber optic sensor systems are completely immune to all forms of electrical interference.

Answer: True