55951. Telecine equipment in a TV studio consists of
55952. TV signal strength when expressed in dB m has the reference of
55953. A sinusoidal voltage amplitude modulates a carrier of peak value 5 kV. Each side band has an amplitude of 500 V. The modulation index is
55954. Kell factor is about
55955. An antenna has a resistance of 50 Ω and an equivalent noise resistance of 30 Ω The noise figure in decibels is
55956. An MTI radar operating at 5 GHz has a PRF of 800 pps. The lowest blind speed is
55957. For maximum output the width of air gap of audio head should be
55958. The simplest mixer circuit for public address system uses
55959. PAM stands for
55960. In a perfect conductor the resistor noise is
55961. An RF carrier of 12 kV at 1 MHz is amplitude modulated by 1 kHz signal having peak value of 6 kV. The modulation pattern is seen on CRO screen. The voltage indicated will be
55962. In push pull amplifier, each transistor conducts for
55963. In the television system in India, each channel is allowed a bandwidth of
55964. A diode detector load consists of 0.01 μF capacitor in parallel with a 5 k ohms resistor. The maximum depth of modulation without diagonal clipping at modulating frequency of 1000 Hz and 10 kHz is
55965. A Discone antenna is
55966. In a two tone AM system the two modulating frequencies are 2000 p and 4000 p rad/sec. If carrier frequency is 2p x 106 rad/sec the frequencies of upper sidebands are
55967. For a system to be designated as hi-fi, the signal to noise ratio should be at least
55968. Dolby system of noise reduction divides the total audio spectrum into
55969. In a system an input resistance of 20 kΩ causes a noise voltage of 15μV. If two such input resistances each of 20 kΩ are used in parallel, the total noise voltage will be about
55970. In the television system in India, the odd and even fields are scanned
55971. Consider the following A signal f(t) and its Hilbert transform fh(t) have the same energy density spectrumA signal f(t) and its Hilbert transform, fh(t) have the same auto correlation functionA signal f(t) and its Hilbert transform are mutually orthogonal Which of the above are true?
55972. Vidicon and plumbicon operate on the principle of
55973. A TV receiver has a width of 60 cm. The aspect ratio is 4/3. The required EHT supply is about
55974. The typical squelch circuit
55975. A narrow band noise n(t) has symmetrical spectrum and has power density spectrum 0.2 x 10-6. The power density of quadrature component is
55976. The radio receivers mostly used now a days are
55977. The reactance of coupling capacitors, for DC quantities, is
55978. An AM wave is given by s(t)AM = 20 (1 + 0.5 cos 103t + 0.3 cos 104 t cos 106 t) the modulation index of the envelope is
55979. The modulating frequency in frequency modulation is increased from 10 kHz to 30 kHz. The bandwidth is increased by
55980. A sinusoidal signal with peak to peak amplitude of 1.536 volt is quantized into 128 levels using a mid-rise uniform quantizer. The quantization noise power is
55981. An FM wave is made to pass through a frequency tripler. If original modulation index is mf, the output of tripler has a modulation index equal to
55982. A balun provides an impedance transformation of
55983. A signal m(t) with bandwidth 500 Hz is first multiplied by a signal g(t) where . The resulting signal is then passes through an ideal low pass filter with bandwidth 1 kHz the output of the low pass filter would be
55984. If γ = (S0/N0)/(Si/Nm) where S0 and S1 are signal power output and signal power input and N0 and Nm are noise power output and noise power input, the value of γ for SSB-SC and DSB-SC amplitude modulated system respectively are
55985. Consider the draw backs Slope overloadSerration noiseGranular noise Which of these draw backs does Delta modulation have?
55986. It is required to increase the maximum range of a radar by a factor of two. The peak power transmitted in the radar system has to be increased by a factor of
55987. Armstrong F.M. transmitter performs frequency multiplication in stages
55988. A source generates three symbols with probabilities 0.25, 0.25, 0.50 at a rate of 3000 symbols per second. Assuming independent generation of symbols, the most efficient source encoder would have average bit rate is as
55989. The filter circuit for feeding tweeter has
55990. The name modem is a contraction of terms modulator demodulator.
55991. The use of SSB
55992. In which List of the constitution 'Economic and Social Planning' is included?
55993. Video signals are transmitted through
55994. A TV receiver has 20 kV EHT supply and total beam current (for 3 electron guns) of 1500 μA. The power handled by IHVT is
55995. Some possible disadvantages of high level modulation in TV transmitters are Video monitor has to supply high video voltages upto several hundred volts into highly capacitive loads drawing high current at video frequenciesThe grid modulated stage presents a varying load to its driverThe linearity and high video driving power present design problems Out of above which are true?
55996. Beam width of an antenna is expressed in
55997. In broadcast television, the number of lines per frame is chosen to be odd number to
55998. In a picture tube, the video signal is applied to
55999. If frames are repeated at 60 Hz and each frame has 525 lines, the time for scanning one horizontal line (for progressive scanning and no interlacing) is about