IDIS 300 (true, false)
AC induction motor rotors consist of a laminated cylinder with plastic bars in slots around the outer part of the cylinder.
False
Adjustable-speed drives operate as closed-loop systems only.
False
All personal computers come with an I/O structure.
False
Class H fuses are not renewable.
False
Contactors are non-magnetically operated.
False
DC motors are less complex and costly than corresponding AC induction motors.
False
Inverters or Variable Frequency Drives (VFD) were developed to control the voltage and frequency to DC motors.
False
LVDT is the abbreviation for low voltage digital transformer.
False
Manual starters are the most widely used in the USA for motors over 2 HP
False
Motors that are recognized as meeting North American standards for hazardous locations also can be assured to meet IEC.
False
One seldom needs to be concerned with environmental conditions when selecting adjustable-speed drives.
False
PLCs are unable to work with any form of local are network (LAN) communication.
False
Piezoresistive sensors are based on the principle that resistance of the same element changes with humidity.
False
Tachometer-generators are used to measure speed of light.
False
The Canadian equivalent of NEMA is NAFTA.
False
Thyristors are current amplifiers that can start and stop conduction upon command.
False
Wound-rotor drives are available in ratings from fractional hp to 40 HP.
False
A dough mixer is a typical constant-horsepower application.
True
AC motor starters connect an AC motor to and disconnect it from an electrical power source.
True
AC motor stators contain windings with two or more magnetic poles per phase.
True
AC motors contain two main parts-the stator and the rotor.
True
AC motors typically direct on AC power lines.
True
AC starters employ two basic components and an overload
True
Adjustable-speed drives change the output speed of an electric motor.
True
All adjustable-speed drives provide a means for starting, stopping, and adjusting the output speed of the drive.
True
Analog regulators process current and voltage signals in analog form.
True
Both mechanical and electrical adjustable-speed drives are widely used in conveyor applications.
True
Bubble sensors are popular for water and waste treatment applications.
True
CSI drives regulate current rather than voltage.
True
D-flange motors have clearance holes without threads and can be directly bolted on to machinery.
True
Electric motors operate on the principle that a force acts on a conductor when it carries current in a magnetic field.
True
Encoders are used for both position and speed feedback.
True
Limit switches translate motion into switch actuation.
True
Locked-rotor torque available at zero speed for accelerating the load.
True
Message displays provide information in response to various control events.
True
Motor controllers often contain relays, push buttons, and manually operated switches.
True
Photoelectric sensors produce a voltage when exposed to light.
True
Polyphase motors are available in ratings from fractional to thousands of horsepower.
True
Power semiconductors are used in electrical adjustable-speed drives.
True
Regenerative braking provides negative torques at any speed.
True
Sensors are devices that respond to a physical stimulus such as heat, light, pressure and flow.
True
Solid-state control techniques make step less control possible.
True
Solid-state starters can use current-limit ramping or tachometer feedback to produce different acceleration and deceleration characteristics.
True
Solid-state starters have an "energy-saver" function.
True
Solid-state starters use an intelligent regulator module similar to those used in adjustable-speed DC drives.
True
Some belted adjustable-speed drives are with remote electrical speed adjustment and speed indicators.
True
Starters designed to meet NEMA and IEC standards differ in three important characteristics-ratings, life, and overload types.
True
The majority of general-purpose, three-phase motors manufactured after October 24, 1997 are required to meet EPACT.
True
The rotational speed of the stator's magnetic field is called the synchronous speed of the motor.
True
The size of a PLC memory is defined in so many "K"
True
The term "inverter" refers to equipment that produces an AC output from a DC input.
True
There are two basic types of DC motors - brush and brushless.
True
Three types of wound-field DC motors included series, shunt, and compound wound.
True
Three-phase motors are reversed by interchanging any two of three power leads to the motor.
True
Vision systems integrate integrate industrial computers with video cameras that provide data about the light it receives.
True
