GATE Electronics and Communication Test 4 Online Question Answer

1. The circuit below implements a filter between the input current i_i and the output voltage v₀. Assume that the opamp is ideal. The filter implemented is a

2. Choose the most appropriate word from the options given below to complete the following sentence:
It was her view that the country's problems had been ______ by foreign technocrats, so that to invite them to come back would be counter-productive.

3. Choose the most appropriate word from the options given below to complete the following sentence:Under ethical guidelines recently adopted by the Indian Medical Association, human genes are to be manipulated only to correct diseases for which _________ treatments are unsatisfactory.

4. A silicon PN junction is forward biased with a constant current at room temperature. When the temperature is increased by 10ºC, the forward bias voltage across the PN junction

5. For the BJT Q_L in the circuit shown below, β = ∞ V_{BEon = 0.7V ,} V_CEsat = o.7 V. The switch is initially closed. At time t = 0, the switched is open. The time t at which Q₁ leaves the active region is

6. In the circuit shown below, the initial charge on the capacitor is 2.5 mC, with the voltage polarity as indicated. The switched is closed time t = 0. The current i(t) at a time t after the switched is closed is:

7. Choose the word from the options given below that is most nearly opposite in the meaning to the given word:
Frequency

8. A Zener diode, when used in voltage stabilization circuits, is biased in:

9. In the circuit shown below, capacitors C₁ and C₂ are very large and are shorts at the input frequency . v is a small signal input . The gain magnitude |V₀/V₁| at 10 M rad/s is:

10. The modes in a rectangular waveguide are denoted by TE_mn/TM_mn where m and n are the eigen numbers along the larger and smaller dimensions of the waveguide respectively.  Which one of the following statements is TRUE?

11. The channel resistance of an N-channel JFET shown in the figure below is 600Ω when the full channel thickness (t_ch) of 10μm is available for conduction. The built in voltage of the gate P⁺ N junction (V_bi) is -1 V. When the gate to source voltage (V_GS) is 0 V, the channel is depleted by 1μm on each side due to the builtin voltage and hence the thickness available for conduction is only 8μm.

The channel resistance when V_GS = -3 V is:

12. The channel resistance of an N-channel JFET shown in the figure below is 600Ω when the full channel thickness (t_ch) of 10μm is available for conduction. The built in voltage of the gate P⁺ N junction (V_bi) is -1 V. When the gate to source voltage (V_GS) is 0 V, the channel is depleted by 1μm on each side due to the builtin voltage and hence the thickness available for conduction is only 8μm.
The channel resistance when V_GS = 0 V is:

13. In the circuit shown below, the network N is described by the following matrix:

14. In the circuit shown below, the Norton equivalent current amperes with respect to the terminals P and Q is:

15. The first six points of the 8-points DFT of a real valued sequence are 5, 1 - j3, 0, 3 - j4. The last two points of the DFT are respectively:

16. The output Y in the circuit below is always '1' when

17. A transmission line of characteristic impedance 50W is terminated in a load impedance Z_L. The VSWR of the line is measured by 5 and the first of the voltage maxima in the line is observed at a distance of λ/4 from the load. The value of Z_L is:

18. Given that f(y) = |y|/y, and q is any non-zero real number, the value of | f(q) - f(-q) is:

19. The value of the integral ∮_c -3z + 4 / (z² + 4z + 5)    dz where c is the circle |z| = 1 is given by

20. In the circuit shown below, assume that the voltage drop across a forward biased diode is 0.7 V. The thermal voltage V = kT/q = 25mV. The small signal input v_i = V_p cos (ωt) where V_p = 100mV.

The ac output voltage v_ac is:

21. The logic function implemented by the circuit below is (ground implies logic 0)

22. The root locus plot for a system is given below. The open loop transfer function corresponding to this plot is given by:

23. In the circuit shown below, for the MOS transistors, μ_nC_ox = 100μA/V² and the threshold voltage V_T = 1V. The voltage V_x at the source of the upper transistor is:

24. The trignometric Fourier series of an even function does not have the:

25. In the unit step response of a network is (1 - e^-αt), then its unit impulse response is:

26. In the circuit shown below, assume that the voltage drop across a forward biased diode is 0.7 V. The thermal voltage V = kT/q = 25mV. The small signal input v_i = V_p cos (ωt) where V_p = 100mV.

The bias current I_DC through the diodes is:

27. A numerical solution of the equation f(x) = x + √x-3 = 0 can be obtained using Newton Raphson method. If the starting value is x = 2 for the iteration, the value of x that is to be used in the next step is:

28. A measure signal m(t) = cos 200πt + 4 cosπt modulates the carrier c(t) = cos 2π f_ct where f_c = 1 MHZto produce an AM signal. For demodulating the generated AM signal using an envelope detector, the time constant RC of the detector circuit should satisfy:

29. When the output Y in the circuit below is 'I',  it implies that data has:

30. In the circuit given below, the value of R_L such that the power transferred to R_L is maximum is:

31. Drift current in the semiconductors depends upon:

32. The circuit shown below is driven by a sinusoidal input v_i = V_p cos (t/RC). The steady state output v₀ is:

33. An analog signal is band-limited to 4kHz, sampled at the Nyquist rate and the samples are quantized in to 4 levels. The quantized levels are assumed to be independent and equally probable. If we transmit two quantized samples per second , the information rate is _________ bits/second.

34. The solution of the differential equation
 = ky, y(0) = c is

35. A transmission line of characteristic impedance 50Ω is terminated by a 50Ω load. When excited by a sinusoidal voltage source at 1GHz, the phase difference between two points spaced 2mm apart on the line is found to be π/4 radians. The phase velocity of the wave along the line is:

36. The system of equations
x + y + z = 6
x + 4y + 6z = 20
x +4y + λz = μ
has NO solution for values of λ and μ given by:

37. For a BJTthe common base current gain α = 0.98 and the collector base junction reverse bias saturation current I_CO = 0.6μA. This BJT is connected in the common emitter mode and operated in the active region with a base drive current I_B = 20μA. The collector current I_C for this mode of operation is:

38. There are two candidates P and Q in an election. During the campaign, 40% of the voters promised to vote for P, and rest for Q. However , on the day of election 15% of the voters went back on their promise to vote for P and instead voted for Q. 25% of the voters went back on their promise to vote for Q and instead voted for P. Suppose, P lost by 2 votes, then what was the total number of voters?

39. A fair dice is tossed two times. The probability that the second toss results in a value that is higher than the first toss is:

40. An input x(t) = exp (-2t)u(t) + δ(t-6) is applied to an LTIsystem with impulse response h(t) = u(t). The out put is: