JEE Main2013PhysicsCommunication SystemActual
Which of the following statement is NOT correct?
Options
- AGround wave signals are more stable than the sky wave signals.
- BThe critical frequency of an ionospheric layer is the highest frequency that will be reflected back by the lay
- CElectromagnetic waves of frequencies higher than about 30 MHz cannot penetrate the ionosphere.
- DSky wave signals in the broadcast frequency range are stronger at night than in the day time.
Correct answer
C. Electromagnetic waves of frequencies higher than about 30 MHz cannot penetrate the ionosphere.
Step-by-step solution
Above critical frequency (f_c ) , an electromagnetic wave penetrates the ionosphere and is not reflected by it.