Q1. What are the x, y, and z values of a MEMS accelerometer when the phone is held with y-axis tilted 30° from the surface and x-axis is parallel to surface? You can assume that the phone is still, i.e., the user is not moving.
Q2. What are the x, y, and z values of a MEMS accelerometer when the phone is held with x-axis tilted 60° from the surface and y-axis is parallel to surface? You can assume that the phone is still, i.e., the user is not moving.
Q3. A phone is resting on the table in front of you in the portrait mode with y-axis pointing away from you. If you push the phone to the left causing a linear acceleration of 3m/s2, what are the x, y, and z readings you can expect from the accelerometer?
Q4. You have just rotated a phone, which was resting on the table, completely around its z-axis (360-degree rotation) with a uniform angular speed. The rotation took you 6 seconds to complete. What would be the computed total angular displacement based on gyro readings if the gyro had a bias (offset) of 0.02 in its z-axis. Note that MEMS gyros report values in radians and there are 2π radians in a circle.
Q5. A MEMS magnetometer is using a 1 cm straight wire with 10µA current flowing through it. If it records a Lorentz force of 10 Newton, what is the magnetic force in Tesla?
Q6. Compute the magnetic heading of a phone lying horizontal on the floor given the following x and y magnetometer readings (in micro tesla):
(a) Mx = 50, My = 50
(b) Mx = -50, My = 10
(c) Mx = 0, My = 50
(d) Mx = 0, My = -50
Q7. For the readings in Q1, calculate the true heading or the following cities (ignore the minutes and seconds of the declination angle value available from IGRF):
(a) Sydney
(b) New York
(c) London
(d) Tokyo
Q8. You are measuring the magnetic field in Sydney, Australia, using your smartphone magnetometer. Which of the following readings indicate that there is likely to be some magnetic perturbation (give your reason)?
