Q. Point out the correct statement. (Solved)

1. mems is a class of very small sensor or actuator devices where small mechanical systems are driven by electricity to indicate a position

2. the incorporation of low-cost geo-sensors in the form of gps chips into mobile devices opens the mobile user to a whole range of services based on the client’s location

3. the iphone uses the proximity sensor to turn the screen off when a user puts the phone to his face