You were close. This is Faraday's Law of Induction.

The flux is \(\displaystyle\phi={N}{B}{A}{\cos{\theta}}\)

N is the number of turns

B is the strength of the magnetic field (should be in T)

A is the area of the loop (should be in \(\displaystyle{m}^{{2}}\))

The angle is between the magnetic field and the normal(perpendicular to the coil) so it would be cos(90.0 - 28.0).

The EMF = - rate of change in flux, or

\(\displaystyle{E}{M}{F}={\frac{{-\triangle\phi}}{{\triangle{t}}}}\)

The \(\displaystyle\triangle\phi={N}{B}{\left(\triangle{A}\right)}{\cos{\theta}}\) (since A is the only thingthat changes, and you don't need the original A, only the change in A)

\(\displaystyle\triangle={1.80}{s}\)

If the above still confuses you...

Flux Linkage, or simply flux, refers to the magnetic field linespassing through the area of a loop:

The diagram on the left shows the loop allows the magnetic fieldvectors to pass through it (\(\displaystyle\theta\) ˜ 0 deg), but on the right,the magnetic field vectors cannot pass through it (\(\displaystyle\theta\) = 90deg).

The flux is \(\displaystyle\phi={N}{B}{A}{\cos{\theta}}\), so in the case on the cos (0deg) = 1, so \(\displaystyle\phi={N}{B}{A}\), but on the right cos (90 deg) = 0, so \(\displaystyle\phi={0}\).

The way that \(\displaystyle\theta\) is defined is it is perpendicular to the planeof the loops. Think about how the diagram on the right has a \(\displaystyle\theta\)= 90 deg. The area vector is pointing straight out at us in theright figure.

The flux is \(\displaystyle\phi={N}{B}{A}{\cos{\theta}}\)

N is the number of turns

B is the strength of the magnetic field (should be in T)

A is the area of the loop (should be in \(\displaystyle{m}^{{2}}\))

The angle is between the magnetic field and the normal(perpendicular to the coil) so it would be cos(90.0 - 28.0).

The EMF = - rate of change in flux, or

\(\displaystyle{E}{M}{F}={\frac{{-\triangle\phi}}{{\triangle{t}}}}\)

The \(\displaystyle\triangle\phi={N}{B}{\left(\triangle{A}\right)}{\cos{\theta}}\) (since A is the only thingthat changes, and you don't need the original A, only the change in A)

\(\displaystyle\triangle={1.80}{s}\)

If the above still confuses you...

Flux Linkage, or simply flux, refers to the magnetic field linespassing through the area of a loop:

The diagram on the left shows the loop allows the magnetic fieldvectors to pass through it (\(\displaystyle\theta\) ˜ 0 deg), but on the right,the magnetic field vectors cannot pass through it (\(\displaystyle\theta\) = 90deg).

The flux is \(\displaystyle\phi={N}{B}{A}{\cos{\theta}}\), so in the case on the cos (0deg) = 1, so \(\displaystyle\phi={N}{B}{A}\), but on the right cos (90 deg) = 0, so \(\displaystyle\phi={0}\).

The way that \(\displaystyle\theta\) is defined is it is perpendicular to the planeof the loops. Think about how the diagram on the right has a \(\displaystyle\theta\)= 90 deg. The area vector is pointing straight out at us in theright figure.