Plant Operator Selection System Test Plant Operator Selection System Physics Principles 5

Question 1

In a series electrical circuit, if one component fails open (breaks), what happens to current flow?

Accepted Answer

Current stops completely throughout the circuit

Answer

In a series circuit there is only one path for current; an open break stops all current flow in the entire loop.

Question 2

A flywheel is used on a reciprocating engine primarily to:

Accepted Answer

Store rotational energy and smooth out power pulses

Answer

Flywheels store kinetic energy during power strokes and release it during non-power strokes, smoothing rotational speed.

Question 3

Which condition causes cavitation in a centrifugal pump?

Accepted Answer

Suction pressure falling below the fluid's vapor pressure

Answer

Cavitation occurs when local pressure drops below vapor pressure, forming vapor bubbles that collapse and damage impeller surfaces.

Question 4

Work is defined as:

Accepted Answer

Force multiplied by distance in the direction of the force

Answer

Work (W) = Force (F) × Distance (d) in the direction the force acts; applying force without movement does no work.

Question 5

Which type of valve is best suited for fully open or fully closed service and NOT for flow throttling?

Accepted Answer

Gate valve

Answer

Gate valves are designed for on/off isolation; partial opening causes erosion, vibration, and poor flow control.

Plant Operator Selection System Test Practice Test