You are looking down on a single coil in a constant magnetic field B = 1.2 T which points directly into of the screen. The dimensions of the coil go from a = 8 cm and b = 17 cm, to a* = 16 cm and b* = 22 cm in t = 0.04 seconds. If the coil has resistance that remains constant at 1.2 ohms. What would be the magnitude of the induced current in amperes?

Respuesta :

Answer:

The  current is [tex]I = 0.5425 \ A[/tex]

Explanation:

From the question we are told that

   The  magnetic field is  [tex]B = 1.2 \ T[/tex]

   The first length is  [tex]a = 8 \ cm = 0.08 \ m[/tex]

    The  second length is  [tex]a^* = 16 \ cm = 0.16 \ m[/tex]

    The first width is  [tex]b = 17 \ cm = 0.17 \ m[/tex]

     The second  width is  [tex]b^* = 22 \ cm = 0.22 \ m[/tex]

    The time interval  is  [tex]dt = 0.04 \ s[/tex]

     The resistance is  [tex]R = 1.2 \ \Omega[/tex]

Generally the first area is

     [tex]A = a * b[/tex]

=>    [tex]A = 0.08 * 0.17[/tex]

=>     [tex]A = 0.0136 \ m^2[/tex]

The second area is  

      [tex]A^* = a^* * b^*[/tex]

=>   [tex]A^* = 0.16 * 0.22[/tex]

=>     [tex]A^* = 0.0352 \ m^2[/tex]

Generally the induced emf is mathematically represented as

       [tex]\epsilon = - \frac{ B * [A^* - A]}{dt}[/tex]

This negative show that it is moving in the opposite direction of the motion producing it

=>   [tex]|\epsilon | = \frac{ 1.2 * [ 0.0352-0.0135]}{0.04}[/tex]

=>    [tex]|\epsilon | = 0.651 \ V[/tex]

The induced current is

     [tex]I = \frac{|\epsilon|}{R}[/tex]

=>   [tex]I = \frac{ 0.651}{1.2}[/tex]

=>   [tex]I = 0.5425 \ A[/tex]