Electromagnetic Field Theory
A rectangular waveguide is a

Rectangular conducting wire to propagate electromagnetic waves
Hollow rectangular walled room carrying electromagnetic wave
Tube antenna to transmit and receive electromagnetic waves
Hollow rectangular conducting tube through which electromagnetic waves can be propagat-ed

ANSWER DOWNLOAD EXAMIANS APP

Electromagnetic Field Theory
Inside a hollow conducting sphere

 electric field changes with distance from the center of the sphere.
 electric field is zero.
 electric field is a non zero constant.
 electric field changes with magnitude of the charge given to the conductor.

ANSWER DOWNLOAD EXAMIANS APP