Respuesta :
Explanation:
Given that,
Area enclosed by a brass bracelet, [tex]A=0.005\ m^2[/tex]
Initial magnetic field, [tex]B_i=3.1\ T[/tex]
The electrical resistance around the circumference of the bracelet is, R = 0.02 ohms
Final magnetic field, [tex]B_f=0.93\ T[/tex]
Time, [tex]t=16\ ms=16\times 10^{-3}\ s[/tex]
The expression for the induced emf is given by :
[tex]\epsilon=-\dfrac{d\phi}{dt}[/tex]
[tex]\phi[/tex] = magnetic flux
[tex]\epsilon=-\dfrac{d(BA)}{dt}[/tex]
[tex]\epsilon=-A\dfrac{d(B)}{dt}[/tex]
[tex]\epsilon=-A\dfrac{B_f-B_i}{t}[/tex]
[tex]\epsilon=-0.005 \times \dfrac{0.93-3.1}{16\times 10^{-3}}[/tex]
[tex]\epsilon=0.678\ volts[/tex]
So, the induced emf in the bracelet is 0.678 volts.
Using ohm's law to find the induced current as :
V = IR
[tex]I=\dfrac{V}{R}[/tex]
[tex]I=\dfrac{0.678}{0.02}[/tex]
I = 33.9 A
or
I = 34 A
So, the induced current in the bracelet is 34 A. Hence, this is the required solution.
