Suppose that a 0.375 m radius 500 turn coil produces an average emf of 12000 V when rotated one-fourth of a revolution in 4.27 ms, starting from its plane being perpendicular to the magnetic field. what is the peak emf generated by this coil, in volts?

Respuesta :

Answer:

epsilon_{peak}= 18833 V

Explanation:

Average emf

[tex]\epsilon_{avg} =\frac{NAB}{\Delta t}[/tex]

⇒ [tex]B=\frac{\epsilon_{avg}\Delta t}{NA}[/tex]

[tex]=\frac{12000\times4.27\times10^{-3}}{500\times\pi 0.375^2}[/tex]

solving this we get

B=0.2320 T

No. of revolutions are 1/4 rev

Δθ= [tex]\frac{1}{4}2\pi =1.57 rads[/tex]

angular velocity ω = [tex]\frac{\Delta\theta}{\Delta t}[/tex]

= [tex]\frac{1.57}{4.27\times10^{-3}}[/tex]

=367.68 rad/sec

The peak emf

[tex]\epsilon_{peak} =NAB\omega[/tex]

putting values we get [tex]\epsilon_{peak}=500\times\pi\times0.375^2\times0.232\times367.68[/tex]

solving we get

epsilon_{peak}= 18833 V

Answer:

[tex]\epsilon_0=12000\ V[/tex]

Explanation:

Given:

no. of turns in the coil, [tex]n=500[/tex]

area of the coil, [tex]A=\pi\times 0.375^2=0.442\ m^2[/tex]

average emf induced, [tex]\epsilon=12000\ V[/tex]

angle turned by the coil, [tex]\psi=\frac{\pi}{4} \ radians[/tex]

time taken to sweep the given angle, [tex]t=4.27\times 10^{-3}\ s[/tex]

peak emf, [tex]\epsilon_0=? [/tex]

We have the relation between peak emf and average emf as:

[tex]\epsilon=\epsilon_0. sin (\omega t)[/tex] .............................(1)

where:

[tex]\rm \omega= angular\ velocity[/tex]

we already know the value:

[tex]\omega t=\psi=90^{\circ}[/tex]

From eq. (1) we have:

[tex]\epsilon=\epsilon_0. sin(\frac{\pi}{4})^c [/tex]

[tex]\epsilon=\epsilon_0[/tex]

[tex]\epsilon_0=12000\ V[/tex]