The eigen values of a skew-symmetric matrix are

•  (A) always zero
•  (B) always pure imaginary
•  (C) either zero or pure imaginary
•  (D) always real

The trigonometric Fourier series for the waveform f(t) shown below contains

•  (A) only cosine terms and zero value for the dc component
•  (B) only cosine terms and a positive value for the dc component
•  (C) only cosine terms and a negative value for the dc component
•  (D) only sine terms and a negative for the dc component

A function n(x) satisfied the differential equation $\frac{d^{2}n\left(x\right)}{d{x}^2}-\frac{n\left(x\right)}{L^2}=0$ where L is a constant. The boundary conditions are: n(0)=K and n ( ∞ ) = 0. The solution to this equation is

•  (A) n(x) = K exp(x/L)
•  (B) n(x) = K exp(-x/ $\sqrt{L}$)
•  (C) n(x) = K² exp(-x/L)
•  (D) n(x) = K exp(-x/L)

For the two-port network shown below, the short-circuit admittance parameter matrix is

•  (A) $\left[\begin{array}{cc}4& -2\\ -2& 4\end{array}\right]S$
•  (B) $\left[\begin{array}{cc}1& -0.5\\ -0.5& 1\end{array}\right]S$
•  (C) $\left[\begin{array}{cc}1& 0.5\\ 0.5& 1\end{array}\right]S$
•  (D) $\left[\begin{array}{cc}4& 2\\ 2& 4\end{array}\right]S$

For parallel RLC circuit, which one of the following statements is NOT correct?

•  (A) The bandwidth of the circuit deceases if R is increased
•  (B) The bandwidth of the circuit remains same if L is increased
•  (C) At resonance, input impedance is a real quantity
•  (D) At resonance, the magnitude of input impedance attains its minimum value.

At room temperature, a possible value for the mobility of electrons in the inversion layer of a silicon n-channel MOSFET is

•  (A) 450 cm²/V_-s
•  (B) 1350 cm²/V_-s
•  (C) 1800 cm²/V_-s
•  (D) 3600 cm²/V_-s

Thin gate oxide in a CMOS process in preferably grown using

•  (A) wet oxidation
•  (B) dry oxidation
•  (C) epitaxial deposition
•  (D) ion implantation

In the silicon BJT circuit shown below, assume that the emitter area of transistor Q1 is half that of transistor Q2.

The value of current I₀ is approximately

•  (A) 0.5 mA
•  (B) 2mA
•  (C) 9.3 mA
•  (D) 15mA

The amplifier circuit shown below uses a silicon transistor. The capacitors C_c and C_E can be assumed to be short at signal frequency and the effect of output resistance r₀ can be ignored. If C_E is disconnected from the circuit, which one of the following statements is TRUE?

•  (A) The input resistance R_i increases and the magnitude of voltage gain A_V decreases
•  (B) The input resistance R_i decreases and the magnitude of voltage gain A_V decreases
•  (C) Both input resistance R_i and the magnitude of voltage gain A_V decrease
•  (D) Both input resistance R_i and the magnitude of voltage gain A_V increase

Assuming the OP-AMP to be ideal, the voltage gain of the amplifier shown below is

•  (A) $-\frac{R_2}{R_1}$
•  (B) $-\frac{R_3}{R_1}$
•  (C) $-\left(\frac{R_2||R3}{R_1}\right)$
•  (D) $-\left(\frac{R_2+R3}{R_1}\right)$

Match the logic gates in Column A with their equivalents in Column B.

•  (A) P–2, Q-4, R-1, S-3
•  (B) P-4, Q-2, R-1, S-3
•  (C) P–2, Q-4, R-3, S-1
•  (D) P-4, Q-2, R-3, S-1

For the output F to be 1 in the logic circuit shown, the input combination should be

•  (A) A = 1, B= 1. C = 0
•  (B) A = 1, B= 0,C = 0
•  (C) A = 0, B= 1. C = 0
•  (D) A = 0, B= 0, C = 1

In the circuit shown, the device connected to Y5 can have address in the range

•  (A) 2000 - 20FF
•  (B) 2D00 – 2DFF
•  (C) 2E00 – 2EFF
•  (D) FD00 - FDFF

Consider the z-transform X(z) = 5z² + 4z^-1 + 3; 0<|z| < ∞ . The inverse z transform x[n] is

•  (A) 5δ[n + 2] + 3δ [n] + 4δ [n – 1]
•  (B) 5δ [n - 2] + 3δ [n] + 4δ [n + 1]
•  (C) 5 u[n + 2] + 3 u[n] + 4 u[n – 1]
•  (D) 5 u[n - 2] + 3 u[n] + 4 u[n + 1]

Two discrete time systems with impulse responses h₁[n] = δ [n -1] and h2[n] = δ [n – 2] are connected in cascade. The overall impulse response of the cascaded system is

•  (A) δ [n - 1] + δ [n - 2]
•  (B) δ [n - 4]
•  (C) δ [n - 3]
•  (D) δ [n - 1] δ [n - 2]

For an N-point FFT algorithm with N = 2^m which one of the following statements is TRUE?

•  (A) It is not possible to construct a signal flow graph with both input and output in normal order
•  (B) The number of butterflies in the m^th stage is N/m
•  (C) In-place computation requires storage of only 2N node data
•  (D) Computation of a butterfly requires only one complex multiplication

The transfer function Y(s)/R(s) of the system shown is

•  (A) 0
•  (B) $\frac{1}{s+1}$
•  (C) $\frac{2}{s+1}$
•  (D) $\frac{2}{s+3}$

A system with transfer function $\frac{Y\left(s\right)}{X\left(s\right)}=\frac{s}{s+p}$ has an output $y\left(t\right)=\cos \left(2t-\frac{\mathrm{\pi }}{3}\right)$ for the input signal $x\left(t\right)=p \cos \left(2t-\frac{\mathrm{\pi }}{2}\right)$ Then, the system parameter ‘p’ is

•  (A) $\sqrt{3}$
•  (B) $\frac{2}{\sqrt{3}}$
•  (C) 1
•  (D) $\frac{\sqrt{3}}{2}$

For the asymptotic Bode magnitude plot shown below, the system transfer function can be

•  (A) $\frac{10s+1}{0.1s+1}$
•  (B) $\frac{100s+1}{0.1s+1}$
•  (C) $\frac{100s}{10s+1}$
•  (D) $\frac{0.1s+1}{10s+1}$

Suppose that the modulating signal is m(t) = 2cos (2$\pi$ f_mt) and the carrier signal is x_C(t) = A_C cos(2$\pi$f_ct), which one of the following is a conventional AM signal without over-modulation?

•  (A) x(t) = A_cm(t) cos(2$\pi$f_ct)
•  (B) x(t) = A_c[1 + m(t)]cos(2$\pi$f_ct)
•  (C) x(t) = A_c cos(2$\pi$f_ct) + $\frac{A_c}{4}$m(t) cos(2πf_ct)
•  (D) x(t) = A_c cos(2$\pi$f_mt) cos(2πf_ct) + A_c sin(2πf_mt) sin(2πf_ct)