CET Electrical & Control Systems

Question 1

What is the main function of a relay in elevator control systems?

Accepted Answer

Switch circuits using control signals

Answer

Measure electrical resistance

Answer

Regulate motor speed

Answer

Store electrical energy

Question 2

Which type of motor is commonly used in modern traction elevator systems?

Accepted Answer

AC gearless permanent magnet motor

Answer

DC brushed motor

Answer

AC induction motor

Answer

Stepper motor

Question 3

What is the purpose of a limit switch in elevator systems?

Accepted Answer

Prevent over-travel of the elevator car

Answer

Control car lighting

Answer

Signal for door closing

Answer

Measure speed

Question 4

Which component converts AC to DC for elevator control circuits?

Accepted Answer

Rectifier

Answer

Transformer

Answer

Capacitor

Answer

Resistor

Question 5

What safety component cuts off power during an elevator malfunction?

Accepted Answer

Circuit breaker

Answer

Surge protector

Answer

Voltage stabilizer

Answer

Contactor

Question 6

Which device is used in elevator systems for variable speed control of motors?

Accepted Answer

Variable Frequency Drive (VFD)

Answer

Contactor

Answer

Relay

Answer

Thermostat