How can we measure the strength of magnetic fields on the Sun?
A)by looking for the splitting of spectral lines in the Sun's spectrum
B)by observing the sizes of sunspots: Bigger sunspots mean a stronger field
C)by observing auroras here on Earth
D)only by using sophisticated computer models,because there are no observational ways of measuring magnetic field strength

Question

Quizplus · Accepted Answer

By looking for the splitting of spectral lines in the Sun's spectrum, we can determine the strength of magnetic fields on the Sun. This method is known as Zeeman splitting and is caused by the interaction of magnetic fields with atoms in the Sun's atmosphere.

Answer: B 
 The size of sunspots is related to the strength of the magnetic fields on the Sun. This is because sunspots are caused by the concentration of magnetic fields on the surface of the Sun. Larger sunspots generally indicate stronger magnetic fields.

Answer: D 
 While computer models can be used to simulate magnetic fields on the Sun, there are also observational methods to measure their strength (such as Zeeman splitting). Therefore, it is not accurate to say that there are no observational ways of measuring magnetic field strength on the Sun. Option C is also not accurate since auroras on Earth are caused by the interaction of the Earth's magnetic field with particles from the Sun, and not directly by the magnetic fields on the Sun itself.

How Can We Measure the Strength of Magnetic Fields on the Sun