Question

In a superheterodyne receiver, the IF is $455{\text{ }}kHz$ . If it is tuned $1200{\text{ }}kHz$ , the image frequency will be
A) $1562{\text{ }}kHz$
B) $1675{\text{ }}kHz$
C) $2110{\text{ }}kHz$
D) $2025{\text{ }}kHz$

Answer 1

In a superheterodyne receiver, the station frequency plus we have to do twice the intermediate frequency equal to an image frequency is an undesired input frequency.

Complete step by step answer:
It is given that the question as $455{\text{ }}kHz$ is called the intermediate frequency (IF) of a radio.
Without going into great detail, $455{\text{ }}kHz$ is one of the most commonly used IFs used in the super heterodyne radio.
In a superheterodyne receiver,
IF = $455{\text{ }}kHz$
It is tuned to${\text{1200 }}kHz$
To find the image frequency is
Any signal is capable of interfering with super heterodyne receiver if,
Image frequency = tuned signal$\pm 2 \times I.F$
Tuned frequency = ${\text{1200 }}kHz$ and
IF =$455{\text{ }}kHz$ is given.
Therefore, image frequency $= 1200 \pm 910$
Hence, the image frequency is = ${\text{2110 }}kHz$ or ${\text{290 }}kHz$.

So, the image frequency will be option (C) is ${\text{2110 }}kHz$.

Additional Information: Heterodyning which simply means mixing, superheterodyne receiver works on the principle.
By a local oscillator it is a type of receiver which mixes the received signal frequency with the frequency of the signal generated.
As a known intermediate frequency the output of the mixer provides a lower fixed frequency.
The sum and their difference of the applied frequencies and also their harmonics that can in multiple frequencies applied that is a nonlinear device to produce the new frequencies.

Note: The most suitable type for the great majority of radio receiver applications; the advantages of the super heterodyne receiver make it.
AM, FM, communications, Single-sideband,
Television and even radar receivers all use it,
With only slight modifications in Super heterodyne Principle.