A circular loop of wire with a radius of 15.0 cm and oriented in the horizontal xy-plane is located in a region of uniform magnetic field. A field of 1.5 T is directed along the positive z-direction, which is upward. Of the loop is removed from the field region in a time interval of 2.8 ms , find the average emf that will be induced in the wire loop during the extraction process.

Respuesta :

Answer:

The average emf that will be induced in the wire loop during the extraction process is 37.9 V

Explanation:

The average emf induced can be calculated from the formula

[tex]Emf = -N\frac{\Delta \phi}{\Delta t}[/tex]

Where [tex]N[/tex] is the number of turns

[tex]\Delta \phi[/tex] is the change in magnetic  flux

[tex]\Delta t[/tex] is the time interval

The change in magnetic flux is given by

[tex]\Delta \phi = \phi _{f} - \phi _{i}[/tex]

Where [tex]\phi _{f}[/tex] is the final magnetic flux

and [tex]\phi _{i}[/tex] is the initial magnetic flux

Magnetic flux is given by the formula

[tex]\phi = BAcos(\theta)[/tex]

Where [tex]B[/tex] is the magnetic field

[tex]A[/tex] is the area

and [tex]\theta[/tex] is the angle between the magnetic field and the area.

Initially, the magnetic field and the area are pointed in the same direction, that is, [tex]\theta = 0^{o}[/tex]

From the question,

B = 1.5 T

and radius = 15.0 cm = 0.15 m

Since it is a circular loop of wire, the area is given by

[tex]A = \pi r^{2}[/tex]

∴ [tex]A = \pi (0.15)^{2}[/tex]

[tex]A = 0.0225\pi[/tex]

∴[tex]\phi_{i} = (1.5)(0.0225\pi)cos(0^{o} )[/tex]

[tex]\phi_{i} = (1.5)(0.0225\pi)[/tex]

( NOTE: [tex]cos (0^{o}) = 1[/tex] )

[tex]\phi_{i} = 0.03375\pi[/tex] Wb

For [tex]\phi_{f}[/tex]

The field pointed upwards, that is [tex]\theta = 90^{o}[/tex]. Since [tex]cos (90^{o}) = 0[/tex]

Then

[tex]\phi_{f} = 0[/tex]

Hence,

[tex]\Delta \phi = 0- 0.03375\pi[/tex]

[tex]\Delta \phi = - 0.03375\pi[/tex]

From the question

[tex]\Delta t = 2.8 ms = 2.8 \times 10^{-3} s[/tex]

Here, [tex]N[/tex] = 1

Hence,

[tex]Emf = -N\frac{\Delta \phi}{\Delta t}[/tex] becomes

[tex]Emf = -(1)\frac{-0.03375\pi}{2.8 \times 10^{-3} }[/tex]

[tex]Emf = 37.9 V[/tex]

Hence, the average emf that will be induced in the wire loop during the extraction process is 37.9 V.