56901. In TV systems, equalising pulses are sent during
56902. A carrier A cos ωct is modulated by a signal mt A cos ω1t + m2 A cos ω2t + m3 A cos ω3t. The total modulated power is
56903. A three stage telephone switching structure is to have 128 input and 128 output terminals. There are 16 first stage and 16 third stage matrices. To avoid blocking the number of intermediate paths required is
56904. The main function of a balanced modulator is to
56905. Which of the following is not considered as a useful quantity in comparing noise performance of receivers?
56906. Oscillator crystal is made of
56907. If an isotropic source is radiating power P in all directions, the electric field at a distance d from the source is proportional to
56908. An FM signal has modulating frequency fm and maximum frequency deviation of δ. The bandwidth will be nearly equal to
56909. In a cellular communication system, path loss between transmitter and receiver is due to
56910. Transistor T1 operates at 30 kHz and T2 operates at 300 Hz. The flicker noise is
56911. The buffer overflow attack is caused by
56912. A tape recorder and deck are entirely similar.
56913. Which of the following is not valid IPv4 addresses?
56914. Assertion (A): SSB systems generally have duplex operationReason (R): SSB systems are generally used in two way communication.
56915. Which of the following is an indirect way of generating FM?
56916. When the length of antenna is a whole wavelength
56917. Circular polarization
56918. An FM radio receiver which is tuned to a 91.6 MHz broadcast station may receive an image frequency of __________ MHz.
56919. If S represents the carrier synchronization at the receiver and r represents the bandwidth efficiency, then the correct statement for the coherent binary PSK is
56920. For telegraphy the most commonly used modulation system is
56921. Commercial Frequency deviation of FM is
56922. The colour of an object is decided by
56923. In Pulse Code Modulation system
56924. Waveform shown in figure is that for
56925. Human ear can detect sound intensities of the order of
56926. If output power of a radio receiver is doubled, its volume is increased by __________ dB.
56927. Address resource records are associated with
56928. Which of the following protocols is used in accessing web mail?
56929. To eliminate ghosts in the picture
56930. Consider a sampled signal y(t) = 5 x 10-6 x(t) where x(t) = 10 cos (8p x 103)t and t s = 100 μ sec. when y(t) is passed through an ideal low-pass filter with a cut off frequency of 5 kHz, the output of the filter is
56931. The frequency range of 300 kHz to 3000 kHz is known as
56932. Which of the following does not cause losses in optical fibre cables?
56933. For a low level AM system, the amplifiers modulated stage must be
56934. Assertion (A): In FM the frequency of the carrier is varied by the modulating voltageReason (R): FM and PM are two forms of angle modulation.
56935. A cordless telephone using separate frequencies for transmission in base and portable units is known as
56936. For attenuation of high frequencies we should use
56937. A modem is classified as low speed if data rate handled is
56938. VSB modulation is preferred in TV because
56939. A woofer should be fed from the input through a
56940. If gcd(a,b)=x and gcd(b,c)=y,then gcd(a,c)is
56941. Assuming the same key is used,two occurrences of the same plaintext characters are encrypted as identical output symbols in which of the following
56942. A product cipher is constructed using a combination of
56943. Which of the following characteristics is most widely used in fingerprint recognition?
56944. During the initial stages of an attack by a new internet scanning worm,the number of infected machines increases
56945. A device which converts BCD to seven segment is called
56946. In 2's complement representation the number 11100101 represents the decimal number
56947. A decade counter skips
56948. BCD input 1000 is fed to a 7 segment display through a BCD to 7 segment decoder/driver. The segments which will lit up are
56949. A ring counter with 5 flip flops will have
56950. For the gate in the given figure the output will be