Induced EMF in a moving conductor

Everything You Need in One Place

Homework problems? Exam preparation? Trying to grasp a concept or just brushing up the basics? Our extensive help & practice library have got you covered.

Learn and Practice With Ease

Our proven video lessons ease you through problems quickly, and you get tonnes of friendly practice on questions that trip students up on tests and finals.

Instant and Unlimited Help

Our personalized learning platform enables you to instantly find the exact walkthrough to your specific type of question. Activate unlimited help now!

?
Intros
Lessons
  1. Introduction to induced EMF in a moving conductor.
  2. Magnitude of the electromotive force.
  3. Direction of the induced current and electromotive force.
?
Examples
Lessons
  1. A 1.2m length of wire is pulled through a uniform 0.045 T magnetic field at 6.7m/s as shown. What emf is generated between the ends of the wire?

    Induced EMF in a Moving Conductor.
    1. 0V
    2. 0.090V
    3. 0.36V
    4. 0.45V
  2. A solid conductor travels at 150m/s across a uniform 0.045T magnetic field. Which side is positively charged and what is the emf across this block?

    Induced EMF in a Moving Conductor.
    1. The circular loop of wire shown below has an area of 0.40 m2m^{2} and is in a 0.60T magnetic field. This filed increased to 1.40 T in 0.25 ss.

      Induced EMF in a Moving Conductor.
      1. A 0.050m long conducting wire is moved through a 1.5 T magnetic field as shown below.

        Induced EMF in a Moving Conductor.


        What is the magnitude of the emf generated between its ends, and in what direction do the electrons in the conductor initially move?

        Induced EMF in a Moving Conductor.
        1. A circular loop of resistance 1.2 Ξ© \Omega is pulled a distance of 0.40m into a perpendicular magnetic field as shown below.

          Induced EMF in a Moving Conductor.


          an average current of 0.50A is produced in the coil during this event. Calculate the constant speed with which the coil was pulled.
          1. 0.10 m/s
          2. 0.75 m/s
          3. 1.9 m/s
          4. 2.4 m/s
        2. A 0.75 m conducting rod is moved at 8.0m/s across a 0.25 T magnetic field along rails. The electrical resistance of the system is 5.0 Ξ© \Omega . What are the magnitude and direction through point XX?

          Induced EMF in a Moving Conductor.


          Induced EMF in a Moving Conductor.
          1. A 200-turn coil has a 15.2 V potential difference induced in it when the magnetic field changes from 0.42 T to 0.22 T in the opposite direction in 3.2 ×10?2 ss. What is the radius of this coil?

            Induced EMF in a Moving Conductor.
            1. 3.5 × 10?2m
            2. 5.1 × 10?2m
            3. 5.9 × 10?2m
            4. 6.2 × 10?2m
          Topic Notes
          ?

          In this lesson, we will learn:

          • Moving a conductor in a uniform magnetic field results in an induced emf across the conductor.
          • How to find the magnitude of the electromotive force?
          • How to find the direction of the electromotive force?

          Notes:

          • Moving a conductor in a uniform magnetic field results in an induced emf across the conductor.
          • As the conductor moves, there is a change in magnetic flux, due to the change in area of the conductor that is exposed to the magnetic field lines.

          • Induced EMF in a Moving Conductor.


          • Change in flux results in electromotive force induction and induced emf in the loop.


          • Magnitude of the Electromotive Force


          • According to Faraday’s law:

          Ο΅=ΔϕΔt \large \epsilon = \frac{\Delta \phi} {\Delta t}


          ll = length of the rod
          BB = magnetic field
          vv = speed of the rod
          AA = area of the loop

          If the rod moves at speed of vv , it travels a distance of Ξ”x\Delta x , in a time Ξ”t\Delta t ;

          Ξ”x=vΞ”t \Delta x = v \Delta t

          Therefore, the area of the loop changes by an amount of Ξ”A\Delta A = lΞ”xl \Delta x

          Ο΅=ϕΔt=BΞ”AΞ”t=Blv ΔtΞ”t=Blv\large \epsilon = \frac{\phi} {\Delta t} = \frac{B \Delta A} {\Delta t} = \frac{Blv \, \Delta t} {\Delta t} = Blv



          Direction of the Induced Current and Electromotive Force

          • The direction of the induced current is in a way to oppose the change in flux.

          • Induced EMF in a Moving Conductor.