Question

The dispersion relation for electromagnetic waves travelling in a plasma is given by $ω^2 = c^2k^2-ω^2_ρ$, where c and $ω_ρ$, are constants. In this plasma, group velocity will be

• A. proportional to but not equal to phase velocity
• B. equal to the phase velocity
• C. inversely proportional to the phase velocity
• D. constant

Answer 1

Answer: (C)

inversely proportional to the phase velocity

Answer 2

The correct option is (C):inversely proportional to the phase velocity