Electric fish navigate by responding to changes in the current in seawater. This current is due to a potential difference of around 3.0 VV generated by the fish and is about 11 mAmA within a centimeter or so from the fish. Receptor cells in the fish are sensitive to the current. Since the current is at some distance from the fish, the sensitivity of these cells suggests that they might be responding to the magnetic field created by the current. To get some estimate of how sensitive the cells are, we can model the current as that of a long, straight wire with the receptor cells 1.80 cmcm away. What is the strength of the magnetic field at the receptor cells?

Given Information:

Current = I = 11 mA

Distance = r = 1.80 cm

Required Information:

Strength of Magnetic Field = B = ?

Strength of Magnetic Field = 0.122x10⁻⁶ T

Explanation:

The magnetic field produced in a long straight wire carrying a current and at distance r is given by

B = μ₀I/2πr

Where μ₀ is the permeability of free space and its value is 4πx10⁻⁷

11 mA = 0.0110 A

1.80 cm = 0.0180 m

B = 4πx10⁻⁷*0.0110/2π* 0.0180

B = 0.122x10⁻⁶ T

Therefore, the strength of magnetic field at the receptor cells of electric fish is 0.122x10⁻⁶ T

absorption lines are where light has been absorbed by the atom thus you see a dip in the spectrum whereas.

emission spectra have spikes in the spectra due to atoms releasing photons at those wavelengths.

explanation:

probably not the "magnets"in the magnet, so to speak, are thought to be electrons orbiting in shells. vurrent loops two sides to the loop