26. If the system T.F. is The differential equation representing the system is
27. Fullerene is an allotrope of?
28. The antenna current of an AM transmitter is 8 A, when only the carrier is sent, but it increases to 8.93 A when the carrier is modulated by a single sine wave. Determine the antenna current when the percent of modulation changes to 0.8
29. A noiseless 3 KHz channel can transmit binary at the rate __________ .
30. Find Vx Vy Vz
31. If x[n] then the sequence x[n] is
32. The impulse response and the excitation function of a linear time invariant causal system are shown in figure (a) and (b) respectively. The output of the system at t = 2 sec is equal to
33. Consider a stable and causal system with impulse response h(t) and system function H(S). Suppose H(S) is rational, contains a pole at S = - 2, and does not have a zero at the origin. The location of all other poles and zero is unknown for each of the following statements. Let us determine whether statement is true or false. f[h(t) e-3t] convergesh(t) has finite durationH(s) = H(- s) Choose correct option.
34. The specific gravity of tungsten is 13.8 and its atomic weight is 184.0 Assume that there are two free elements per atom. Then the Fermi level or characteristic energy for the crystal in eV will be
35. An air-filled rectangular waveguide has dimensions 8cm x 10cm . The phase velocity of guided wave at frequency of 3 GHz for TE10 mode is
36. For a = - 1, find the value of V2
37. A unity-feedback control system has the open loop transfer function . If the input system is a unit ramp, the steady state error will be
38. For a given voltage, four heating coils will produce maximum heat when connected
39. Denominator polynomial of a transfer function of certain network is:
s3 + s2 + 2s + 24
Then the network is:
40. A TV picture is to be transmitted over a channel of 6 MHz bandwidth at a 35 dB S/N ratio. The capacity of the channel is
41. The ratio of the diffusion coefficient in a semiconductor has the units
42. Consider the probability density f(x) = ae-b|x| where x is a random variable whose allowable values range from x = - ∞ to x = + ∞. P(1 ≤ x ≤ 2)
43. The amplitude of a pair of composite sinusoidal signal y(n) = x1(n) + x2(n) with x1(n) = sin (5p n) x2(n) = 3 sin (5p n) is __________ .
44. The amplifier circuit shown below uses a silicon transistor. The capacitors Cc and CE can be assumed to be short at signal frequency and the effect of output resistance r0 can be ignored. If CE is disconnected from the circuit, which one of the following statements is TRUE?
45. A n-channel JFET has IDSS = 2 mA, Gate to source voltage VGS = - 2 V and trans-conductance is 0.5 mW then pinch-off voltage is __________ .
46. If we manage to __________ our natural resources, we would leave a better planet for our children.
47. (2)3 + (3)4 = (?)5
48. If g(t) = e- p t2 then G(0) is __________ (where g(t)⇔ G(f)
49. The open loop transfer function of a unity feedback system is: The range of K for which the system is stable is
50. A discrete time linear shift-invariant system has an impulse response h[n] with h[0] = 1, h[1] = - 1, h[2] - 2, and zero otherwise. The system is given an input sequence x[n] with x[0] - x[2] - 1, and zero otherwise. The number of nonzero samples in the output sequence y[n], and the value of y[2] are, respectively