The figure shows a circular wire of radius a centered at the origin. A
spatially uniform magnetic field points in the z-direction but varies
linearly with time.
a=5.00 cm
B=(0.140 T/s)t
^
k
(a) Calculate the magnetic flux passing through the inside of the wire.
Since the magnetic field is spatially uniform, the flux is
FB
=
B·A
=
[(0.140 T/s)t
^
k
]·[p(0.0500 m)2
^
k
]
=
(1.10×10-3 T·m2/s)t
=
(1.10×10-3 Wb/s)t
(b) Calculate the emf induced in the wire.
E
=
-
dFB
dt
=
-1.10×10-3 Wb/s
=
-1.10×10-3 V
(c) In the figure, draw in the current direction.
ANS: The minus sign indicates that the direction is CW.
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version 3.85. On 28 Mar 2016, 18:04.