A circular coil has a 18.0 cm radius and consists of 25.0 closely wound turns of wire. An externally produced magnetic field of magnitude 3.00 mT is perpendicular to the coil. (a) If no current is in the coil, what magnetic flux links its turns?

The magnetic flux links to its turns = Wb.

Explanation:

Given :

Radius of circular coil = m

Number of turns = 25

Magnetic field = T

Magnetic flux (Φ) is a measure of the magnetic field lines passes through a given area. The unit of magnetic flux is weber (Wb).

We know that,

⇒    Φ =

Where ext. magnetic field, area of loop or coil.

But here given in question, we have turns of wire so our above eq. modified as follows.

⇒   Φ =

Where no. of turns.

∴    Φ =

     Φ =

Thus, the magnetic flux links to its turns =

divide the right side by the left side

0.024÷1.2=0.02 for example

answer: d. a cme increases the amount of energy in the solar wind

explanation:

coronal mass ejections, also called cmes, are large clouds of plasma and magnetic field that erupt from the sun. only when the cloud is aimed at earth will the cme hit earth and therefore cause impacts. high-speed solar wind streams come from areas on the sun known as coronal holes.