# Worksheet: Propagating Electric and Magnetic Fields

In this worksheet, we will practice modeling electromagnetic waves as propagating electric and magnetic fields.

Q1:

Electromagnetic waves propagate through water that has a refractive index of 1.33. The electric permittivity of the water is C2/N⋅m2. What is the magnetic permeability of the water?

• A H/m
• B H/m
• C H/m
• D H/m
• E H/m

Q2:

Which of the following formulas correctly shows the relation between , the speed at which electromagnetic waves propagate through a medium; , the electric permittivity of the medium; and , the magnetic permeability of the medium?

• A
• B
• C
• D
• E

Q3:

At what speed do electromagnetic waves propagate in a vacuum? Answer to two significant figures.

• A m/s
• B m/s
• C m/s
• D m/s
• E m/s

Q4:

Which of the following statements about the energy transferred by the electric and magnetic fields that electromagnetic waves are comprised of is correct?

• AThe energy transferred by the electric field of an electromagnetic wave is equal to the energy transferred by the magnetic field of the electromagnetic wave.
• BThe energy transferred by the magnetic field of an electromagnetic wave is greater than the energy transferred by the electric field of the electromagnetic wave.
• CThe energy transferred by an electromagnetic wave is equal to the difference between the energy transferred by the wave’s electric and magnetic fields.
• DThe energy transferred by the electric field of an electromagnetic wave is greater than the energy transferred by the magnetic field of the electromagnetic wave.

Q5:

Electromagnetic waves propagate through rubber that has a refractive index of 1.5. The electric permittivity of the rubber is C2/N⋅m2. What is the magnetic permeability of the rubber?

• A H/m
• B H/m
• C H/m
• D H/m
• E H/m

Q6:

Which of the following diagrams correctly shows how the electric field , shown in yellow, and the magnetic field , shown in green, that an electromagnetic wave is comprised of vary with time ?

• A
• B
• C
• D

Q7:

A material has an electric permittivity of C2/N⋅m2 and a magnetic permeability of H/m. What is the refractive index of the material?