Automation System
Light sensors:

work in direct sunlight
None of these
come in a wide variety of mounting styles
cannot be used a s limit switches.
never use infrared light as light source

ANSWER DOWNLOAD EXAMIANS APP

Automation System
Stepping motors:

All of these
can run both clockwise and counterclockwise
do not require commutators
can be built to index different amounts by changing the pole configuration
can run at varying speeds

ANSWER DOWNLOAD EXAMIANS APP

Automation System
A venturi tube:

is extremely difficult to use
can be used to measure gas or liquid flow rates
None of these
measures the presence of a liquid
is made only of metal

ANSWER DOWNLOAD EXAMIANS APP