56701. Satellite communication uses frequencies in the range of
56702. In a channel voice coder, the outputs of sixteen 20 Hz low pass filters are sampled, multiplexed and A/D converted. If sampling is at 40 samples/second and 3 bits/sample represents each voltage sample, the bit rate is about
56703. Super high frequency means more than 3000 MHz.
56704. Impedance inversion may be obtained with
56705. Which of the following can be used to convert PPM into PWM?
56706. For an antenna of height ht metres, the radio horizon is equal to
56707. If in a radio receiver, RF signal has a frequency of 800 kHz and local oscillator that of 1000 kHz, then at the output of the mixer, the frequencies found would be __________ kHz.
56708. In the stabilized reactance modulator AFC system
56709. In AM, the modulation envelope has a peak value double the unmodulated carrier level, when the modulation is
56710. Which of the following is correct (FDM means Frequency Division Multiplexing and TDM means Time Division Multiplexing)?
56711. Consider the following applications/ advantages of radar beacons navigationtarget identificationaccurate tracking of enemy targetslarge increase in maximum range Which of the above are correct?
56712. The signal plate of vidicon tube is coated with tin oxide.
56713. The maximum permissible distance between two samples of a 10 kHz signal
56714. In telephone systems, load is expressed in the unit of
56715. Which of the following microphones has bidirectional feature?
56716. In TV transmitter some possible advantages of IF modulation are The modulator section and visual exciter can be solid state devicesVSB filter can be introduced at low power levelThe subsequent stages following VSB filter can be tuned permanently for wideband linear operationIt is economical which of the above are true?
56717. As compared to AM, FM requires
56718. Capture effect occurs in
56719. If there are M messages and each message has probability , the entropy is
56720. Narrowband FM signal can be considered to be equal to
56721. The spectral component of noise associated with kth frequency is given, in the limit as Δf → 0 by nk(t) written as nk(t) = Ck cos (2p k Δft + θk)
Consider the following statements as regards Ck and θk Ck and θk are independent of one anotherCk and θk are independent of the amplitude of a spectral component at a different frequencyCt and θk are independent of the phase of a spectral component at a different frequency Which of the above statements are correct?
56722. A narrowband amplifier is one that has a passband
56723. In a modulator it is found that the amplitude spectrum consists a component at fc, the carrier frequency and one component each at fc - fs and fc + fs where fs is the modulating signal frequency. Then the modulator used is
56724. Chest compression rate in CPCR according to 2015 guidelines is
56725. Troposphere is the portion of atmosphere
56726. Earth's curvature affects the effective height of antenna.
56727. In PCM, the quantization noise depends on
56728. In high power AM transmission, modulation is done at
56729. The noise sources shot noise, partition noise and thermal noise are associated with which component
56730. Consider the following statements as regards communication receiver Variable sensitivity is used to eliminate selective fadingA product demodulator can be used to receive Morse codeThe noise limiter cuts off receiver output during a noise pulseDouble conversion is used to improve image rejection Which of the above statements are correct?
56731. In a transmission line, losses due to dielectric heating are
56732. The power rating of radio transmitters is around
56733. How can the quantizing noise be reduced?
56734. Audio systems use transverse recording.
56735. In a CD player the laser uses
56736. Leak type bias is used in a plate-modulated class C amplifier to
56737. FM broadcast is done using
56738. A CW transmitter radiates
56739. The commonly employed filter in SSB generation is
56740. The storage capacity of a CD is
56741. Which of the following pulse modulation is analog?
56742. Pulse stuffing is used in
56743. Household taperecorders generally use
56744. In AM receiver the oscillator frequency is
56745. The modulation index of an AM wave is measured using a CRO. The waveform is as shown in figure, the modulation index is nearly
56746. A photo diode converts light signals to binary.
56747. A three stage telephone switching structure is to have 128 input and 128 output terminals. It has been found that at peak time the utilization probability is 0.1. The number of intermediate links required for non-blocking configuration is 15. If the actual number of intermediate links is 5, the probability of blocking of call is
56748. In pulse code modulation, if the signal is sampled at the rate of f and the number of pulses in one code group is p, then the number of pulses per second will be