Selectivity of a receiver & Advantages of an RF amplifier

Selectivity of a receiver:

Options:

a.) Changes with incoming signal frequency
b.) Is poorer at high frequencies
c.) Is the rejection of the adjacent channel at the receiver
d.) All of the above

Correct Answer: All of the above

Explanation:

The ability of the receiver to select the wanted signals among the various incoming signals is termed as Selectivity. It rejects the other signals at closely lying frequencies. Selectivity is determines performance of a radio receiver that how much it responds only to the radio signal that is required to receive. Selectivity of a receiver changes with incoming signal frequency and is poorer at high frequencies

Advantages of using an RF amplifier are:

Options:

a.) Better selectivity
b.) Better sensitivity
c.) Improved signal to noise ratio
d.) All of the above

Correct Answer: All of the above

Explanation:

The RF amplifiers have greater gain that is they have better sensitivity. They have better ability to amplify weak signals received by the receiver. The RF amplifiers have better selectivity i.e., better ability to select the wanted signals among the various incoming signals. The incoming weak signals are raised to a higher level by the RF amplifiers and therefore they improve signal to noise ratio.