56351. In a FM signal, the modulation index increases, then the power
56352. Higher order TDM levels are obtained by
56353. Assertion (A): In AM, use of SSB reduces the power and bandwidth requirementReason (R): A balanced modulator produces AM with carrier suppressed
56354. Limiter is not essential in the following detector
56355. An FM signal is modulated by an 8 kHz sine wave and has maximum and minimum frequencies of 100.05 MHz and 99.95 MHz respectively. Its deviation frequency is
56356. Assertion (A): RF tuner is called front end of TV receiverReason (R): RF tuner receives the TV signal and selects the required channel.
56357. In TV broadcast, UHF range is
56358. The most commonly used microphone for public address systems is
56359. Pre-emphasis and De-emphasis is done by using R-C circuit.
56360. Which of the following is Doppler effect not used?
56361. If the AF voltage is raised to 10 V, while the AM is dropped to 200 Hz, what is the deviation?
56362. In pulse code modulation when the maximum frequency in the signal is fmax the bandwidth required will be
56363. The oscillator frequency is set for
56364. The main advantage of DM over PCM is
56365. Chrome signals in PAL colour television system consist of
56366. In TV system in India, each frame is divided into
56367. In PAL system
56368. Among the various modulation systems, the most favoured from the point of linearity of modulation and efficiency is
56369. The phase of colour subcarrier burst in PAL is along the axis at
56370. Which of the following is correct (fm is maximum usable frequency, S is speed and G is width of air gap)?
56371. She is good ......... Mathematics .?
56372. In a hi-fi system the frequency response over the audio frequency range should be within
56373. Multiplex techniques are used for
56374. In delta modulation, the output signal to quantization noise ratio S0/Nq is (N is the number of bits)
56375. In an AM system, doubling of modulation index doubles the antenna current. The system is
56376. A frequency multiplier stage should operate as
56377. All are true about ‘Wartenberg syndrom’EXCEPT
56378. A carrier signal at frequency 100 MHz is frequency modulated with modulation index 2 by a signal at 2 kHz. At what frequencies are the sidebands produced?
56379. Which is not purpose of modulation?
56380. An FM transmitter has maximum frequency deviation of 75 kHz and reproduces audio signals up to 15 kHz. Minimum channel width required is __________ kHz.
56381. A 360 W carrier is simultaneously modulated by two audio wave with modulation percentage of 55 and 65 respectively. Total sideband power radiated will be
56382. In a radio detector
56383. ISDN stands for
56384. Under identical conditions, for a single modulating frequency, FM and PM are indistinguishable. Now if the modulating frequency is reduced, then
56385. The main advantage of superheterodyne receiver is
56386. PAL system was proposed first in
56387. MCVF telegraphy causes
56388. Consider the following statements as regards noise If Gaussian noise is applied at input of a rectifier, the output is not gaussianThe noise encountered on a telephone line consists of short, pulse type disturbances whose amplitude distribution is not GaussianShot noise results from random emission of electrons from a cathodeShot noise results from phenomenon associated with the flow of current across semi conductor junctions Which of the above are correct?
56389. Noise can be reduced by increasing sampling rate
56390. In tape recorder erase head is active during recording.
56391. Which of the following microphones has maximum distortion?
56392. The relation between bandwidth B, modulating frequency fm and frequency deviation Δf for a sinusoidally modulated FM signal is
56393. FM broadcast is used in
56394. The power requirement of a RADAR used in military operations is
56395. The percentage saving in power when the carrier and one of the sidebands are suppressed in an AM wave modulated to a depth of 100% will be nearly
56396. The difference between phase and frequency modulation
56397. A signal m(t) amplitude modulates a carrier Ac cos ωct. The final signal will be
56398. An oscillator at 4.2 MHz is followed by two frequency doublers and two triplers. The output frequency will be
56399. Over which frequency range the effect of atmospheric noise is significant?
56400. The author of Wealth of Nations was .........?