A flat coil of wire is used with an LC-tuned circuit as a receiving antenna. The coil has a radius of 0.30 m and consists of 420 turns. The transmitted radio wave has a frequency of 1.3 MHz. The magnetic field of the wave is parallel to the normal of the coil and has a maximum value of 1.7 x 10-13 T. Using Faraday's Law of electromagnetic induction and the fact that the magnetic field changes from zero to its maximum value in one-quarter of a wave period, find the magnitude of the average emf induced in the antenna in this time.

The average  emf induce is  

Explanation:

From the question we are told that

  The radius of the coil is  

   The number of turns is  

    The frequency of the transition radio wave is  

     The magnetic field is  

     The time taken for the magnetic field to go from zero to maximum is

The period of the transmitted radio wave is  

    So  

 The potential difference can be mathematically represented as

Where  

substituting values

ill do it for 100, also this isnt 80 its 40

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.