Electromagnetic Field Theory - Study Mode
[#211] Two identical copper wires W 1 and W 2 placed in parallel as shown in the figure, carry currents I and 2I, respectively, in opposite directions. If the two wires are separated by a distance of 4r, then the magnitude of the magnetic field [overrightarrow B ] between the wires at a distance r from W 1 is
Correct Answer
(D) [frac{{5{mu _0}I}}{{6pi r}}]
[#212] When a dielectric is placed in an electric field, the electric flux density D, electric field intensity E and polarization P are related as
Correct Answer
(D) $$overline { ext{D}} = {varepsilon _0}overline { ext{E}} + { ext{P}}$$
[#213] Gilbert is a unit of
Correct Answer
(B) magneto motive force
[#214] If $${vec a}$$ is a constant vector and $$vec r = xhat i + yhat j + zhat k,$$ xa0 xa0then div $$left( {vec a imes vec r}
ight)$$ xa0and curl $$left( {vec a imes vec r}
ight)$$ xa0are given by
Correct Answer
(C) $$left( {0,,2vec a}
ight)$$
[#215] A material is described by the following electrical parameters at a frequency of 10 GHz σ = 10 6 mho/m, µ = µ 0 and ∈/∈ 0 = 10. The martial at this frequency is considered to be $$left( {{ in _0} = frac{1}{{36pi }} imes {{10}^{ - 9}}{ ext{F/m}}}
ight)$$
Correct Answer
(A) a good conductor