What is a motion sensor?

English Grammar Tests, Elementary Level

ESL/EFL Test #290 [color=blue]“Electronic Devices (1)”, question 1

A -sensor is a security device that turns on an outdoor light if someone walks near the device.

(a) speaker
(b) motion
© move
(d) jog

English Grammar Tests, Elementary Level

ESL/EFL Test #290 [color=blue]“Electronic Devices (1)”, answer 1

A motion-sensor is a security device that turns on an outdoor light if someone walks near the device.

Correct answer: (b) motion
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is move-sensor right?

No, this is a specific technical term. You may hear some people speaking about a ‘movement sensor’, but the correct term is ‘motion sensor’.