ACR-108 Unit 13 Pre-Assessment

The liquid-vapor mix in a partial liquid/partial vapor-filled control is referred to as a

• Subcooled liquid

• Superheated fluid

• Flammable fluid

• Volatile liquid

Which of the following best describes the makeup of a diaphragm?

• Thin, flexible steel

• Thick, rigid steel

• Thick, flexible steel

• Thin, rigid steel

Which of the following is created when a set of electrical contacts opens or closes?

• An overcurrent condition

• A power surge

• A complete electric circuit

• An electric arc or spark

A ______ varies its resistance to current flow based on its temperature.

• thermistor

• thermometer

• thermocouple

• thermopile

In a “rod and tube”-type control device,

• the rod pushes a mechanical linkage to open or close a valve or set of electrical contacts.

• the rod, when heated, pushes against the tube to open or close a valve or set of electrical contacts.

• the tube pushes a mechanical linkage to open or close a valve or set of electrical contacts.

• the mechanical linkage pushes against the tube to open or close a valve or set of electrical contacts.

The component part of a control that operates on the fluid expansion concept is the

• thermocouple.

• thermopile.

• transducer.

• diaphragm.

All of the following devices rely on the principle that different metals expand and contract at different rates except the

• thermocouple.

• rod and tube.

• heat motor valve.

• snap disc.

The Bourdon tube reacts to changes in

The component part of a fluid-expansion control that serves to connect the location where temperature is sensed to the point of control is called the

• cold junction.

• capillary tube.

• transmission line.

• thermocouple.

When a bimetal device is heated, the steel expands faster than the brass, which causes the device to warp.

• True

• False