Photoresistor and phototransistor sensor

Photoresistor sensor is made of a _________________ material

• Insulator

• Conductor

• Semiconductor

A photoresistor is an electronic component whose electrical resistance ________________________________when it is exposed to light.

• changes

• increases

• doesn't change

Phototransistor sensor is a __________________ that reacts to brightness

• sensor

• feeler

• indicator

To build a light barrier in a car parking gate mechanism we need a _____________ .

• Photoresistor sensor

• Phototransistor sensor

We use a __________________ to switch off the light automatically.

• Photoresistor sensor

• Phototransistor sensor

The output of the _________________ is only one or zero.

• digital sensor

• passive sensor

A sensor that has a negative pole and a positive pole it means it has ___________.

• resistance

• polarity

Resistance of photoresistor sensor is low in brightness

• True

• False

Phototransistor sensor is an indicator for the brightness of the light.

• True

• False

Phototransistor sensor doesn't have polarity

• True

• False