Question

Medical devices implanted inside the body are often powered using transcutaneous energy transfer (TET), a type of wireless charging using a pair of closely spaced coils. And emf is generated around a coil inside the body by varying the current through a nearby coil outside the body, producing a changing magnetic flux. Calculate the average induced emf, of each 10-turn coil has a radius of 1.50 cm and the current in the external coil varies from its maximum value of 10.0 A to zero in 6.25 x10-6s.

Answer 1

`0.475\ \text{V}`

Step-by-step explanation:

n = Number of turns = 10

r = Radius = 1.5 cm

I = Current = 10 A

t = Time =
`6.25* 10^(-6)\ \text{s}`

`\mu_0` = Vacuum permeability =
`4\pi* 10^(-7)\ \text{H/m}`

Magnetic field is given by

`B=(\mu_0I)/(2r)\\\Rightarrow B=(4\pi 10^(-7)* 10)/(2* 1.5* 10^(-2))\\\Rightarrow B=0.00042\ \text{T}`

EMF is given by

`\varepsilon=(nBA)/(t)\\\Rightarrow \varepsilon=(10* 0.00042* \pi (1.5* 10^(-2))^2)/(6.25* 10^(-6))\\\Rightarrow \varepsilon=0.475\ \text{V}`

The average induced emf is
`0.475\ \text{V}`.