When an automobile moves over a wide, closed loop of wire embedded in a road surface, is the magnetic field of the Earth within the loop altered? Is a pulse of current produced? Can you cite a practical application for this at a traffic intersection?

  1. 👍
  2. 👎
  3. 👁
  1. There is a redistribution of the Earth's feld lines due to the steel in the car. This causes the flux through the wired to change and a small emf to be generated. This can cause a pulse of current to flow. This can be amplified to detect the presence of the car. This can be used at intersections to activate green lights and determine the length of time that the light remains green.

    Small vehicles like bicycles and motor scooters often do not activate such detectors. This can cause long waits at intersections with not much car traffic.

    I hate it when that happens.

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics EM

    Ive tried multiple answers but cant get it right. Which of the following changes would induce an electromotive force (emf) in the loop? When you consider each option, assume that no other changes occur. a. The magnitude of B_vec

  2. math

    A road perpendicular to a highway leads to a farmhouse located 8 mile away.An automobile travels past the farmhouse at a speed of 80 mph. How fast is the distance between the automobile and the farmhouse increasing when the

  3. physics

    A wire loop has an area of 0.12 m2, and the magnetic field through it increases from 0 to 0.20 T in 0.30 s. What is the induced emf in the loop?

  4. physics EM

    Shrinking Loop. A circular loop of flexible iron wire has an initial circumference of 167 cm, but its circumference is decreasing at a constant rate of 10.0 cm/s due to a tangential pull on the wire. The loop is in a constant


    The rotating loop in an AC generator is a square 11.0 cm on a side. It is rotated at 60.0 Hz in a uniform field of 0.800 T. Calculate the following quantities as functions of time t, where t is in seconds. (a) the flux through the

  2. Physics

    A toy car moves around a loop-the-loop track. The loop is 0.5 m high.What is the minimum speed of the car at the top of the loop for it to stay on the track?

  3. physics (thanks)

    in the context of the loop and junctions rules for electrical circuits a junction is: a) where a wire is connected to a resistor b) where a wire is connected to a battery c) where only two wire are joined d) where three or more

  4. physics.

    please check my answers. when a lamp is plugged into a 120 V socket, each coulomb of charge that flows in the circuit is raised to a potential engergy of 120 joules? which offers more resistance to water flow, a wide pipe or

  1. Physics

    An infinitely long wire carries a current I=100A. Below the wire a rod of length L=10cm is forced to move at a constant speed v=5m/s along horizontal conducting rails. The rod and rails form a conducting loop. The rod has

  2. Physics

    A single conducting loop of wire has an area of 7.4 10-4 m2 and a resistance of 110 Ω. Perpendicular to the plane of the loop is a magnetic field of strength 0.18 T. At what rate (in T/s) must this field change if the induced

  3. Physics

    A 2.00 cm x 2.00 cm square loop of wire with resistance 1.30×10^−2 Ohms is parallel to a long straight wire. The near edge of the loop is 1.00 cm from the wire. The current in the wire is increasing at the rate of 110 A/s. What

  4. physics

    A long, vertical, straight wire carries a current I going upwards. The wire is perpendicular to the plane of a circular metal loop and passes through the center of the loop. The loop is allowed to fall and maintains its

You can view more similar questions or ask a new question.