If the intermediate frequency is very high (indicate false statement)

Solution (By Examveda Team)

Intermediate Frequency (IF):
In radio receivers, the intermediate frequency (IF) is the frequency to which a carrier wave is shifted as part of the process of modulation and demodulation. It is used in superheterodyne receivers to simplify the processing of signals. The IF allows for better control over amplification and filtering.
Correct Answer Explanation:
The question asks about the effects when the intermediate frequency is very high. Let's break down each option:
Option A: Image frequency rejection is very good
This statement is false. In fact, when the intermediate frequency is very high, image frequency rejection tends to worsen. This is because the image frequency is more likely to fall close to the desired signal, making it harder for the receiver to distinguish between the two. Hence, a high IF generally complicates image frequency rejection, not improves it.
Option B: The local oscillator need not be extremely stable
This statement is false. In fact, when the IF is high, the local oscillator must be very stable. This is because the local oscillator frequency determines the IF, and any instability can cause errors in frequency conversion, leading to distortion or interference.
Option C: The selectivity will be poor
This statement is true. As the IF frequency increases, the selectivity (the ability of a receiver to isolate a specific signal from other frequencies) typically decreases. High IF frequencies make it harder to achieve narrow filtering bandwidths, reducing selectivity.
Option D: Tracking will be improved
This statement is true. Tracking refers to the ability of a receiver to follow changes in the input signal. When the IF is high, the receiver has a better ability to track signals over a broader frequency range, as the frequency conversion process is more sensitive to variations in the input signal.
Summary:
The false statement is Option A: "Image frequency rejection is very good," because a high intermediate frequency generally makes it more difficult to reject image frequencies.