In an amplitude modulated system if the total poweris 600W and the power in the carrier is 400W,the modulation index is
ISRO Scientist or Engineer Electronics 2011
For the following questions answer them individually
The channel capacity under the Gaussian noise environment for a discrete memoryless channel with a bandwidth of 4MHz and SNRof31 is.
In satellitecommunication, frequency modulation is used becausesatellite channel has
For a 3-um-diameteroptical fiber with core and cladding indexes of refraction of 1.545 and 1.510, respectively. The cut off wavelengthis.
A 12-bit ADC is operating with a lus clock period and total conversion time is seen to be 14us always. The ADC mustbe of the type
Consider the analog signal $$x(t) = 3 \cos 100 \pi t$$. If the signal is sampled at 200 Hz,the discrete time signal obtained will be
In VHDLall the statements written inside a process statement are ......
A microprocessor with 12-bit address bus will be able to access ...... kilobytes of memory
A practical current source is usually represented by
The dominant mode in a rectangular wave guide is TEo, because this mode has
A PN junction in series with a 100 ohm resistor is forward biased so that a current of 100 mA flows. If voltage across the combination is instantaneously reversed to 10 V at time t = 0, the reverse current that flows through the junction at t= 0 is approximately given by.
Ripple factor for a half waverectifier is ......
........ is a primitive that can execute code. It contains an instruction pointer (=program counter) and sometimes has its own stack
If the $$\alpha$$ and $$\beta$$ are the roots of the equation $$x^{2} + px + q = 0$$, then $$\sum \alpha^{2}$$ is
A signal $$m_{1}$$ (t) is band limited to 3.6 kHz and the three other signals $$m_{2}(t), m_{3}(t)$$ and $$m_{4}(t)$$ are band limited to 1.2 kHz each, and these signals are transmitted by means of TDM. Then, what will be the transmission bandwidth of the channel.
For a 10 bit PCM system the signal to quantization noise ratio is 62dB. If the number of bits is increased by 2, then the signal to quantization noise ratio will
The modulation normally used with the digital data is
The critical angle $$\theta c$$ in an optical fiber is given by .............. Where $$n_1$$, is refractive index of medium 1 and $$n_2$$ is the refractive index of medium 2.
In a JK flip flop we have J = Q’ and K = 1. Assuming that the flip flop was initially cleared and clocked for 6 pulses, the sequence at the Q output will be
Which of the following system is linear
Which of the following operator cannot be synthesized by VHDL synthesis tools
Which of the following statements with reference to a generic microprocessor is correct?
An electric iron designed for 110V AC supply was rated at 500W. It was put across a 220V supply. Assuming that at 110V it supplied 500W output(i.e no losses) at the new voltage it will supply
A very lossy, $$\frac{\lambda}{4}$$ long, 50 ohm transmission line is open circuited at the load end. The input impedance measured at the other end of the line is approximately.
For the 2N338 transistor, the manufacturer specifies P max =100mW at $$25^\circ C$$ free air temperature and the maximum junction temperature, Tj max = $$125^\circ C$$. Its thermal resistance is
In a Class AB amplifier, the current flows through the active device for
Whichof the following is not true regarding a preemptive kernel
The solution of differential equation $$\frac{dy}{dx} = e^{x - y} + x^{2} e^{-y}$$ is
The intermediate frequency of a super-heterodyne receiver is 450 KHz. If it is tuned to 1200 KHz, the image frequency will be
The bandwidth of a ‘N’ bit binary coded PCM signal for modulating a signal having bandwidth of 'f' Hz is
Go-stationary satellites are placed in equatorial orbits at the height approximately
For a single mode optical cable with 0.25dB/km loss, the optical power 100km from a 0.l1mW source will be .....
The function of a strobe function in digital system is
The impulse responseof a linear time invariant system is h (n) = {1,2, 1,-1}. The response for the input signal x(n) = {1,2,3,1} is
Which of the following statement regarding a constantis not true
In a 3085 microprocessor system with memory mapped $$\frac{I}{O}$$
The Thevenin and Norton circuits are
A broadside array operating at 100 cm wavelength consist of 4 half wave dipoles spaced 50 cm apart. Each element carries radio frequency current in the same phase and of magnitude 0.5 A. The radiated power will be .................. if the radiation resistance is 146 ohm.
An NPN transistor has a beta cutoff frequency $$f_{\beta}$$, of 1MHz, and a common emitter short circuit low frequency current gain $$\beta_{o}$$, of 200. its unity gain frequency $$f_{\gamma}$$ and the alpha cut-off frequency f, respectively are
Fora class B amplifier providing a 20V peak signal to 16 ohm load and a power supply of $$V_{cc}$$= 30V,the efficiency will be.
When a microprocessorinterfaces with a peripheral or memory device, the normaltiming of the microprocessor may need to be altered by introducin
$$\int_{0}^{\frac{\pi}{2}} (\cos^{3} x)dx =$$
In phase modulatedsignal, the frequency deviation is proportional to
For a fast communication which of the following requirements have to be met
For an earthstation transmitter input power of 40dBW (10,000W), with a back
off loss of 3dB, a total branching and feeder loss of 3dB, and a transmit antenna
gain of 40 dB, determine the EIRP.
................ is used to describe the light gathering or light collecting ability of an optical fiber
............ has the maximum fan out capacity
If $$Z$$ transform of $$x(n)$$ is $$X(z)$$ then the $$Z$$ transform of $$x(n - k)$$ is .............
The following code will implement a ................
process (clk, d) begin
if (clk = ‘1’) then
$$q \leq 4d$$;
end if;
end process
The greatest negative number which can be stored in a 8-bit register using 2’s complement arithmetic is
Two coupled coils have self inductances $$L1 = 10mH$$ and $$L2 = 20mH$$. The co-efficient of coupling (K) being 0.75 in the air. Voltage in the second coil when the current in circuit is given by $$I = 2 \sin (314 t) A$$ is..........
In aradarsystem,if the peak transmitted poweris increased by a factor of 16 and the antenna diameteris increased by a factor of 2, then the maximum range will increase by a factor of
The transconductance g_ of an FET in the saturation region equals
The transistor amplifier with 85% of efficiency is likely to be
A run-time stack cannot be used in a round-robin scheduling system because of the _.................. nature of scheduling.
$$(3 + i)/(5 + 5i)$$ is same as
The modulation index of an amplitude modulated waveis changed from 0 to 1. the transmitted power is
In a communication system, each message(1 or 0) is transmitted three times in order to reduce the probability of error. The detection is based on the majority rule at the receiver. If Pc is the probability of bit error, the probability of error for this communication channel will be
Fora satellite transponder with a receiver antenna gain of 12 dB , an LNA gain of 10 dB, and equivalent noise temperature of $$26 dBK^{-1}$$, the $$\frac{G}{Te}$$ is
............currentis the leakage current that flows through a photo diode with no input used in as light detectors.
The figure of merit of a logic family is given by
............... is defined as the time delay that a signal component of frequency $$\omega$$ undergoesas it passes from the input to output of the system.
Which statementis true regarding a behavior modeling in VADL
The process of imitating one system with anotherso that the imitating systems accepts the samedata, executes same programs and achieves sameresults as the imitated systems is known as
The values of R, L and C in series RLC circuit that resonates at 1.5 KHz and consumes 50W from a 50V ac source operating at the resonant frequency. The bandwidth is 0.75 KHz.
When VSWR is 3, the magnitude of the reflection co-efficient will be
The conductivity of the intrinsic germanium at $$300^\circ$$K is . When, $$n_{i}$$; at $$300^\circ K = 2.5 X 10^{13}/cm$$ and $$\mu_{n}$$, and $$\mu_{p}$$, in germanium are 3800 and 1800 cm$$^2$$/Vs respectively.
As comparedto a full waverectifier using 2 diodes, the four diode bridge rectifier has the dominant advantage of
In a real time system, the simplest scheme that allows the operating system to allocate memory to two processes simultaneously is ............
$$(\cos 5 \theta - i \sin 5 \theta)^{2}$$ is same as
In case of which of the following, an increase on the modulation index leads to increase in bandwidth
Four voice signals, each limited to 4 kHz and sampled at Nyquist rate, are converted into binary PCM signal using 256 quantisation levels. The bit transmission rate for the time division multiplexing signal will be
If a counter having 10 FFsis initially at 0, what count will it hold after 2060 pulses?
The output of a circular convolution performed on two signals $$x_{1}(n) = {\underline{2}, 1, 2, 1}$$ and $$x_{2}(n) = {\underline{1}, 2, 3, 4}$$ is
Whenusing a sequential code to design a combinational logic in VHDL,if complete truth table is not defined, the synthesis tool will implement a which is not required.
In whatorder the elements of a pushdownstack are accessed?
What is the value of C such that equivalent capacitance across x - y is 5F
A wave guide section in a microwave circuit will act as a
24V, 600mW Zeneris to be used for providing a 24V stabilized supply to a variable load. Assume that for proper Zener action, a minimum of 10 mA must flow through the Zener. If the input voltage is 32V, what would be the value of R and the maximum load current?
The value of x at which y has a minimum for $$y = x^{2} - 3x + 1$$ is
