Question

The ionospheric layer acts as a reflector for the frequency range:
A) $1\,KHz$ to $10\,KHz$
B) $3$ to $30\,MHz$
C) $100\,KHz$ to $1\,MHz$
D) $3\,GHz$ to $30\,GHz$

Answer 1

Hint: The atmospheric layer of the earth is divided into many layers depending on its nature. They include the troposphere, stratosphere, mesosphere, thermosphere, ionosphere and the exosphere. All these layers together are called the atmosphere.

Complete step by step solution:
The ionosphere is the layer of the earth that is the ionized part starting from the distance of the $48\,Km$ from the earth surface and extends up to the $965\,Km$. The ionosphere layer is of three types as $D$ layer, $E$ layer and the $F$ layer based on the wavelength of the absorbed solar radiation. Out of which the $D$ ionospheric layer located at the bottom, $E$ ionospheric layer at the middle and both interfere with the thermosphere and the mesosphere.

The $F$ ionospheric layer at the top. This layer is provided with the abundant number of the electrons along with the ionized molecules and the atoms. This layer of ionosphere reflects the light waves that are within the frequency range of $3$ to $30\,MHz$ . Above or below this range, may pass through it.

Thus the option (B) is correct.

Note: The atoms and the molecules present in the ionosphere get ionized by the solar radiations from the sun. Hence they conduct the electricity. Due to the process of ionization, this layer of the atmosphere is with a higher temperature.