76. In a broadcast superheterodynes receiver having no RF amplifier, the loaded Q of the antenna coupling circuit is 100. If the intermediate frequency is 455 kHz. In receivers operating upto the limit of shortwave broadcasting the local oscillator often used is
77. In an FM signal, the power
78. An unmodulated voltage 10 V effective is applied to a dioxide detector in which load resistance is 4 x 10-5 ohms. A micrometer shows that the rectified DC current in this resistance is 30 A. The efficiency of detection is
79. Selectivity varies with receiving frequency, frequency is raised.
80. FM receivers using the standard 88 to 108 MHz band use IF of
81. Most of the amplification of the received signal is obtained in a superheterodyne receiver from the
82. The problem associated with tuned-radio frequency receiver is
83. Superheterodyne receiver can be used in
84. In a receiver, at higher frequencies
85. Which of the following circuit cannot be used to demodulate SSB?
86. High IF in a superheat receiver
87. A communication channel with additive white Gaussian noise, has a bandwidth of 4 kHz and an SNR of 15. Its channel capacity is
88. In a superheterodyne receiver
89. The function of an AM detector circuit is to
90. Which of the following should be used in order to prevent overloading or the last IF amplifier in a receiver?
91. Most popular IF for receivers tuning to 540 to 1650 kHz is