Question

In short wave communication waves of which of the following frequencies will be reflected back by the ionospheric layer, having electron density 10¹¹ per m³
(a) 2 MHz(b) 10 MHz(c) 12 MHz(d) 18 MHz

Answer 1

Answer :- In short wave communication waves of which of the following frequencies will be reflected back by the ionospheric layer, having electron density 10¹¹ per m³
(a) 2 MHz(b) 10 MHz(c) 12 MHz(d) 18 MHz

Answer 2

Answer:(a) 2 MHz is the correct answer.

Explanation:

Given data

electron density= 10¹¹ per m³

There is short wave communication.

To find

frequency that will be reflected back by the ionospheric layer=?

Short wave communication makes use of short wave frequency.

It isn't used much lately.

The short wave frequency is usually amplitude modulating frequencies.

The frequency of reflected ray is given by the formula

= 9n^½

n is the energy density of electrons.

The reflected frequency is also known as carrier frequency.

It is denoted by Uc.

Uc= 9n^1/2

Hence,

According to the given data

Uc= 9√10¹¹

= 2.8*10^6Hz

=2.8MHz

Thus the reflected frequency is equal to 2.8MHz which is approximately equal to 2MHz.