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TANGEDCO AE EC 2015 Official Paper

Option 2 : 1.5 × 10^{8} m/s

CT 1: Determinants and Matrices

2903

10 Questions
10 Marks
12 Mins

__Concept:__

The phase velocity (V_{p}) of a plane electromagnetic wave is given as-

\({V_p} = \frac{1}{{\sqrt {\mu \varepsilon } }}\)

Here, μ = μoμr

ε = εo εr

\({v_p} = \frac{1}{{\sqrt {{\mu _o}{\mu _r}{\varepsilon _o}{\varepsilon _r}} }}\)

\({v_p} = \frac{c}{{\sqrt {{\mu _r}{\varepsilon _r}} }}\)

\(c = \frac{1}{{\sqrt {{\mu _o}{\varepsilon _o}} }} = 3 \times {10^8}\;m/sec\)

μ0 = permeability in free space 4π × 10-7 H/m

εo = permittivity in free space 8.854 × 10-12 C2/Nm2

__Calculation:__

For the medium in question,

µr = 1, εr = 4

\(v_p = \frac{{3 \times {{10}^8}}}{{\sqrt {1 \times 4} }}\)

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