56551. The start of modern computer age was started by the event
56552. At night D layer of ionosphere is absent.
56553. Which of the following is not correct?
56554. Assertion (A): Data communication using digital data must be very accurate.Reason (R): In analog signals redundancy is available but in digital signals redundancy is not available.
56555. What is the RF amplifier plate voltage when the audio-modulating voltage is +600 V?
56556. FM has
56557. The service area of a TV transmitter is a little beyond radio horizon.
56558. If carrier power is P and amplitude modulation index is m, the total power after modulation is
56559. Bit is a unit of
56560. The modulation index of an AM wave is changed from 0 to 1. The transmitted power is
56561. In a radio receiver the input from local oscillator is fed to
56562. A shadow zone does not receive any space wave
56563. A radio frequency signal contains the following three frequencies :
850 kHz; 865 kHz and 875 kHz
In order to amplify this signal, which of the following amplifier should be selected?
56564. Which of the following pulse-time modulation is least used?
56565. Transit time is considered as significant at
56566. In a colour TV receiver, AGC adjusts the gain of
56567. In pulse transmitter the ratio of time on to time off is called
56568. In figure the output v(t) is
56569. A MASER is a
56570. Which one of the following is correct?
56571. The airlines of spain?
56572. A balanced modulator circuit uses
56573. In a television camera tube, scanning of a picture is done
56574. In communication receivers the fidelity is provided by
56575. Some features of RF stage in good radio receivers is It increases sensitivity by providing amplification to RF signalIt eliminates image frequency interferenceIt increases selectivityIt reduces noise level Which of the above are true?
56576. During amplitude modulation, the phase angle of the modulating voltage changes by
56577. The image frequency of a superheterodyne receiver is
56578. Image frequency rejection mainly depends upon
56579. Which of the following is most likely to be found in an SSB transmitter?
56580. The maximum life time cumulative dose of Adriamycin chemotherapy is
56581. Which of the following is true as regards telephone systems?
56582. SSB can be generated by
56583. Which one of the following cannot be used to remove the unwanted sideband in SSB?
56584. For FM, which of the following statement is not true?
56585. For TV broadcast, picture signal is modulated in
56586. Assertion (A): Stubs, directional couplers and baluns are very commonly used in communication systemsReason (R): Characteristic impedance of a line is an important parameter.
56587. Audio frequency range lies between
56588. Assertion (A): SSB and ISB receivers have good S/N ratioReason (R): SSB and ISB receivers have good suppression of adjacent channels.
56589. De-emphasis circuit is used
56590. The largest gold producing country in the world?
56591. FM broadcast lies in which band?
56592. Which colour picture tube uses slotted aperture mask?
56593. If the circumference of a spherical target is between 1 to 10 wavelength in a radar system, the situation is called
56594. The complete video signal consists of
56595. Which is most important subsystem for recovering and reconstructing signal in a TDM system?
56596. Which one of the following is an indirect way of generating FM?
56597. Companding is used in PCM to
56598. Assertion (A): In AM the amplitude of carrier is made proportional to the instantaneous amplitude of modulating waveReason (R): In AM, frequency of side band = frequency carrier ± frequency of modulating wave.
56599. Pressing a key on telephone set generates two frequencies. The basis for selection of these frequencies is
56600. The orbital period of a geostationary communication satellite is