Deck 4: Relays

Question 1

The OFF delay timer will begin timing when the relay coil is energized.

Answer 1

False

Question 2

The major difference between a standard relay and a contactor is the ____ of the contacts.

A) operation
B) number and size
C) metallic content
D) current carrying capability

Answer 2

D

Question 3

The pneumatic timing relay consists of three units: a relay coil, instantaneous contacts, and ____________________.

Answer 3

time delay contacts

Question 4

The basic use for the contactor is for ____ in resistance heating elements, lighting, magnetic brakes, or heavy industrial solenoids.

A) switching of power
B) time delay
C) increasing impedance
D) regulating voltage

Question 5

Plug-in relays are designed for multiple switching applications at or above 240 V.

Question 6

The two important parts in a relay are the coil and ____________________.

Question 7

The plug-in relay has a distinct advantage in allowing relays to be changed without disturbing the ____________________.

Question 8

The level of voltage at which the relay coil is energized to move the contacts from their normal, unoperated position to their operated position is called ____.

A) inrush current
B) sealed current
C) pickup voltage
D) drop-out voltage

Question 9

It is important to remember that the contacts on a latch coil will NOT return to their unoperated condition unless the unlatch coil is energized.

Question 10

By energizing a coil of the relay, called the latch coil, the latching relay operates. A second coil on the relay, the unlatch coil, must be energized to return the contacts to their unoperated condition. This arrangement is often referred to as a ____.

A) mechanical latching attachment
B) memory relay
C) locking relay
D) solid-state timing relay