Q. A signal cos(2p fmt) modulates a carrier cos(2p fct) using the double-sideband-with-carrier (DSBWC) scheme to yield a modulated signal cos(2p fct) + 0.3cos(2p fmt) cos(2p fct) . The modulation index is___________.(Answer should be rounded off to one decimal place) . Sol: The standard equation of AM is
Q. A pitot-static tube is used to estimate the velocity of an incompressible fluid of density 1 kg/m3. If the pressure difference measured by the tube is 200 N/m2, the velocity of the fluid, assuming the pitot-tube coefficient to be 1.0, is m/s. Sol: Given that, density = 1 kg/m3 Pressure difference (ΔP) = 200
Q. The resistance of a resistor is measured using a voltmeter and an ammeter. The voltage measurements have a mean value of 1V and standard deviation of 0.12 V while current measurements have a mean value of 1 mA with standard deviation of 0.05 mA. Assuming that the errors in voltage and current measurements are
Q. The figure below shows the 𝑖𝑡ℎ full-adder block of a binary adder circuit. Ci is the input carry and Ci+1 is the output carry of the circuit. Assume that each logic gate has a delay of 2 nanosecond, with no additional time delay due to the interconnecting wires. If the inputs Ai , Bi
Q. The total number of Boolean functions with distinct truth-tables that can be defined over 3 Boolean variables is Sol: The total number of Boolean function with distinct truth table will be for n Boolean variables (22n) so for 3 Boolean variables=(223)=256
Q. An 8-bit weighted resistor digital-to-analog converter (DAC) has the smallest resistance of 500 Ω. The largest resistance has a value Sol: In general, in a binary weighted resistor DAC, the relationship between LSB and MSB resistance is given as :LSB Resistance =(2n−1) MSB resistance where, n is the number of bits in the DAC.Given, n=8smallest resistance =500ΩMSB resistance =500Ω∴LSB
Q. In the circuit shown below, initially the switch S1 is open, the capacitor C1 has a charge of 6 coulomb, and the capacitor C2 has 0 coulomb. After S1 is closed, the charge on C2 in steady state is coulomb. Sol: When switch open, Q1 = 6 C, Q2 = 0 C, C1 =
Q. Consider a circuit comprising only resistors with constant resistance and ideal independent DC voltage sources. If all the resistances are scaled down by a factor 10, and all source voltages are scaled up by a factor 10, the power dissipated in the circuit scales up by a factor of Sol: Let the equivalent circuit
Q. A 3 × 3 matrix has eigenvalues 1, 2 and 5. The determinant of the matrix is . Sol: Given that, Eigen values of a matrix λ1 = 1, λ2 = 2, λ3 = 5 From the property of Eigen values, Determinant of a matrix = product of its Eigen values ⇒ Determinant =
A 3 × 3 matrix has eigenvalues 1, 2 and 5. The determinant of the matrix is . Read More »
Q. In a single-mode optical fiber, the zero-dispersion wavelength refers to the wavelength at which the (A) material dispersion is zero. (B) waveguide dispersion is zero. (C) sum of material dispersion and waveguide dispersion is zero. (D) material dispersion and waveguide dispersion are simultaneously zero. Ans: sum of material dispersion and waveguide dispersion is zero.
