|1. There are several ways to induce an e.m.f. in a conductor. Which one of these will not work?
|2. The magnetic flux cutting through a loop of wire is defined as ...
|3. Which of these is the unit for magnetic flux?
|4. "The direction of the induced current in a conductor will be in such a direction so as to oppose the change in flux that created it." This law is called ...
|5. The magnitude of the e.m.f. induced in a conductor is proportional to ...
|6+7. The diagram shows a long wire placed in a magnetic field directed in to the screen.
6. Which of these answers correctly describes the direction of the induced current in the wire when it is moved upwards (up the screen), or moved to the right?
7. In the above diagram, If the field strength is B and the wire of length l is moved with a velocity v, the maximum induced e.m.f. will be E. The experiment is repeated with a shorter wire of length l/4 and moved at a velocity of 3v. To induce the same e.m.f. E in the wire the magnetic field strength must be:
8+9. A coil is rotated at a constant frequency f inside a magnetic field. The induced e.m.f. generated in the coil is shown in this diagram. The peak e.m.f. is E.
8. Which of these four graphs shows the induced e.m.f. when the coil is rotated at a frequency of 2f?
|9. The r.m.s. voltage induced in this coil when rotated at the higher frequency of 2f is: