Technician A says that as the rotational speed of an ABS monitored wheel increases,the voltage generated by the wheel speed sensor also increases.Technician B says that the frequency produced by a truck ABS wheel speed sensor when it is at a standstill should be close to 400 Hz.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Technician A is correct because the voltage generated by a wheel speed sensor in an ABS system does indeed increase as the rotational speed of the monitored wheel increases. This is because the sensor, often a variable reluctance type, generates a signal whose amplitude (voltage) is proportional to the speed of the wheel. Technician B is incorrect because a wheel speed sensor would not produce a frequency, especially as high as 400 Hz, when the vehicle is at a standstill; it generates signals based on wheel movement.