An electric field is given by $$\overrightarrow E = \overrightarrow a {}_x\,{\rm A}\,\,\sin \,\beta ySin\,\,\omega t$$ is present in a charge free medium infinite in extent

(a) Determine the associated magnetic field.
(b) What type of wave does the above field represent?

The cut-off frequency of a waveguide depends upon

A thin dipole antenna is $$\left( {\lambda /15} \right)$$ long, where $$\lambda $$ is the voperating wavelength. If the dipole has a loss resistance of $$1.5$$ ohm determine its
(i) radiation resistance and
(ii) terminal resistance

In an intrinsic semiconductor the free electron concentration depends on