Radio Receiver

In a superheterodyne receiver, the IF is 455 kHz. If it is tuned to 1200 kHz, the image frequency will be

• 1655 kHz

• 2110 kHz

• 745 kHz

• 910 kHz

As compared to tuned radio frequency receivers, which of the following is the advantage of using superheterodyne receivers?

• High gain and better sensitivity

• Better selectivity at high frequencies

• Stability

• Noise suppression

In a radio receiver, if the intermediate frequency is too low, then

• Image-frequency rejection will improve

• Selectivity will be too sharp

• The frequency selectivity of the local oscillator will have to be lowered

• All of the above

In a radio receiver, the local oscillator is tuned to a frequency

• lower than the incoming frequency

• higher than the incoming frequency

• equal to incoming frequency

• None of the above

The output of a diode detector contains

• D.C. voltage

• modulating signal

• RF ripple

• all of the above

A heterodyne frequency changer is called a

• Modulator

• Mixer

• Demodulator

• Frequency translator

In a radio receiver, if the intermediate frequency is too high, then

• Selectivity will be poor

• Tracking difficulties will be least

• Adjacent channel rejection will improve

• All of the above will occur

When a superheterodyne receiver is tuned to 455 kHz, its local oscillator provides a mixer with the input at 1010 kHz. The image frequency is

• 555 kHz

• 1010 kHz

• 1465 kHz

• A. 1920 kHz

FM receivers using the standard 88 to 108 MHz band use IF of

• 8 MHz

• 9.9 MHz

• 10.7 MHz

• 12.2 MHz

The purpose of de-emphasis network in FM receiver is to

• Limit the amplitude of the modulated carrier

• Restore the original amplitude of higher modulating frequencies

• Avoid diagonal clipping

• Avoid negative peak clipping