An emf induced by the motion of the conductor across the magnetic field is a motional electromotive force. We all know that when an electrical conductor is introduced into a magnetic field, due to its dynamic interaction. Emf equation of transformer can be established in a very easy way. The polarity of the induced emf is such that it tends to produce a current that creates a magnetic flux to oppose the change in magnetic flux through the area. In fact, a loop is only needed if we want the induced current i.
Braingenie solving problems involving motional emf using. E vbl where v, b, and l are all perpendicular to each other if the left vertical side of the spinning coil moves at velocity v, the component of v perpendicular to b is v sin. The magnetic field b is into the page, perpendicular to the moving rod and rails and, hence, to the area enclosed by them. Motional emf and application of faradays law youtube. Electromagnetic induction the physics hypertextbook. A galvanometer is connected between two ends of the rails to detect the current flowing due to electromagnetic induction. Let us consider any arbitrary charge q in the conductor pq. Ap physics c derivation of motional emf using faradays law of induction. A 5kv emf was predicted to be induced in the 20km tether while moving at orbital speed in earths magnetic field. Introduces the physics of motional emf which is an application of faradays law. Consider a conducting bar of length l moving through a uniform magnetic field which points into the page, as shown in figure 10.
This equation is true as long as the velocity, field, and length are mutually perpendicular. Improve your skills with free problems in solving problems involving motional emf using the equation emf vbl and thousands of other practice lessons. The emf induced by the motion of a conductor across a magnetic field is called motional emf. Students may erroneously believe we need a complete loop to get. Changing the magnetic flux through a circuit can make a current. Motional emf as electrical power conversion for the space shuttle was the motivation for the tethered satellite experiment. This flux links with both primary and secondary windings. The circuit is completed by a return path through the stationary ionosphere. G now suppose the conducting bar moves through a region of uniform magnetic field b. In general, motional emf around a closed conducting loop can be written as. Page 1 chapter wise theoretical important questions in physics for classxii page 1 electrostatics 1.
Dragging a wire through a magnetic field can make a current. Actually in electrical power transformer, one alternating electrical source is applied to the primary winding and due to this, magnetizing current flowing through the primary winding which produces alternating flux in the core of transformer. From faradays law consider a conducting bar sliding frictionlessly on a ushaped wire at constant velocity to the right. Motional emf, electromotive force, induced emf definition and. Emf equation of transformer turns voltage transformation. If the magnetic flux through a circuit changes, an emf and a current are induced. Deriving expression for motional emf stack exchange. Class 12 physics chapter wise derivation list edurev. As the rod moves with a constant speed v, the charge is also moving with a speed v in the presence of magnetic field b. This concept of motional emf can be explained with the help of the concept of lorentz force acting on free charge carriers of the conductor. Consider the following classical example of a slidewire generator which consists of ushaped.1119 1361 1111 1262 1039 446 1357 253 40 1356 781 1335 207 553 107 426 172 24 1024 964 1255 279 1005 328 1107 208 380 94 1539 364 501 419 969 397 1045 106 700 57 472 217