In mobile phones, when a user puts the phone to his/her ears, the screen goes off. Which is the sensor used for this?

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ALP CBT 2 Electronic Mechanic Previous Paper: Held on 21 Jan 2019 Shift 2
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  1. Motion sensor
  2. Proximity sensor
  3. Vibration sensor
  4. Temperature sensor

Answer (Detailed Solution Below)

Option 2 : Proximity sensor
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1. In mobile phones, during calls, the proximity sensor detects and turns off the screen when the phone is close to our ears. This function saves power and prevents unintentional activation of other functions while engaged in a call.

2. The proximity sensor also helps to automatically turn on the display when we extract the phone from our pocket. 

3. Proximity Sensor also helps to automatic volume control. Some smartphones have features that automatically increase and decrease the volume based on how close or far our hand or ear is from the phone. 

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