In a circuit with a Hall effect sensor and motor, which condition describes the status if no magnetic field is present to close the sensor and start the motor?

In a circuit with a Hall effect sensor and motor, which condition describes the status if no magnetic field is present to close the sensor and start the motor?

• A. Sensor is latched
• B. No magnetic field present to close the Hall effect sensor and start the motor
• C. Motor is running
• D. Overload condition

Answer: (B)

The key idea here is that a Hall effect sensor used to control a motor acts as a magnetic switch: it closes the circuit and starts the motor only when a magnetic field is present. If there’s no magnetic field, the switch stays open, so the motor does not start. That matches the described status: no magnetic field present to close the Hall effect sensor and start the motor. Why the other ideas don’t fit: a latched sensor would imply the switch remains closed after a prior field, which isn’t the case when there’s no field to keep it closed. The motor running would require the field to be present to close the sensor, which isn’t happening here. An overload condition is a fault state unrelated to the absence of a magnetic field.

The key idea here is that a Hall effect sensor used to control a motor acts as a magnetic switch: it closes the circuit and starts the motor only when a magnetic field is present. If there’s no magnetic field, the switch stays open, so the motor does not start. That matches the described status: no magnetic field present to close the Hall effect sensor and start the motor.

Why the other ideas don’t fit: a latched sensor would imply the switch remains closed after a prior field, which isn’t the case when there’s no field to keep it closed. The motor running would require the field to be present to close the sensor, which isn’t happening here. An overload condition is a fault state unrelated to the absence of a magnetic field.