ime t2, the current in the coil is decreasing
at a rate of −0.3 A/s. At this time, what is
the absolute value of the rate of change of the
magnetic
... [Show More] flux through the loop?
Correct answer: 2.52264 × 10−10 V.
Explanation:
dΦmag
dt
=
Φmag
I
·
dI
dt
=
(4.20441 × 10−9 T · m2
)
(5 A) (−0.3 A/s)
= 2.52264 × 10−10 V .
005 (part 5 of 7) 2.0 points
At this time, what is the absolute value of the
emf in the loop?
Correct answer: 2.52264 × 10−10 V.
Explanation:
|emf| =
dΦmag
dt
= 2.52264 × 10−10 V .
006 (part 6 of 7) 2.0 points
What is the magnitude of the electric field at
location P, which is inside the wire?
Correct answer: 1.00373 × 10−9 V/m.
Explanation:
|emf| =
I
C
E~ NC · d
~ℓ = 2π rℓ
E~ NC
⇒
E~ NC
=
|emf|
2π rℓ
=
2.52264 × 10−10 V
2π(4 cm)
= 1.00373 × 10−9 V/m .
007 (part 7 of 7) 2.0 points
Now the wire loop is removed. Everything
else remains as it was at time t2; the current
is still changing at the same rate. What is the
magnitude of the electric field at location P?
Correct answer: 1.00373 × 10−9 V/m.
Explanation:
Removing the loop doesn’t change the curly
electric field, so this answer is the same as in
part 6.
Circular Coil of Wire
008 (part 1 of 2) 5.0 points
A circular coil of wire 4.22 cm in diameter
has a resistance of 4.7 Ω. It is located in
a magnetic field of 0.149 T directed at right
angles to the plane of the coil. The coil is
removed from the field in 0.378 s.
What is the induced emf in the coil? Assume the magnetic flux is reduced linearly.
Correct answer: 0.000551327 V.
Explanation:
According to Faraday’s induction law,
E = −
∆ ΦB
∆t
=
BA
t
=
(0.149 T)
1
4
π (0.0422 m)2
0.378 s
= 0.000551327 V
009 (part 2 of 2) 5.0 points
How much electric energy is lost in the
process?
Correct answer: 2.44463 × 10−8
J.
Explanation:
The electric energy is dissipated when the
current flows through the coil, so
W = P t =
E
2
R
t
=
(0.000551327 V)2
4.7 Ω (0.378 s)
= 2.44463 × 10−8
J [Show Less]