UPSC Electrical Engineering 2022

(a) For the circuit shown in Figure 1(a), find the V_in, V_S and power supplied by the dependent source. (10 marks) (b) Calculate the forward current caused by 0·8 V forward volta…

(a) (i) For the circuit shown in Figure 2(a)(i), initial current through the coil is zero. The switch is closed at time t = 0. Find the time domain expression of current flowing t…

A common-emitter amplifier circuit is shown in Figure 3(a). Neglect r_x and r_o and assume the current source to be ideal. (i) Derive an expression for the midband gain. (ii) Deri…

For the network shown in Figure 4(a)(i) and its excitation function shown in Figure 4(a)(ii), find the response v(t) using convolution by: (i) 's' domain approach. (ii) time domai…

(a) The diagram of Master-Slave S-R flip-flop and the waveform applied to the Master flip-flop is shown in Figure 5(a). Draw the waveform that appears at the output of Slave flip-…

(a) The plane wave E = 30 cos (ωt – z) aₓ V/m in air normally hits a lossless medium (μ = μ₀, ε = 4ε₀) at z = 0. (i) Find reflection coefficient (Γ), transmission coefficient (τ),…

(a) A three-phase, 5 kW, 440 V, 6 pole, star connected synchronous motor having negligible stator resistance and synchronous reactance of 6 Ω is operated at 0·8 rated power factor…

(a) (i) Differentiate between the functions of Decade counter and BCD counter with example. (10 marks) (ii) Draw the diagram of cascading BCD adders to add two three-digit decimal…

(a) A single-phase AC voltage controller is feeding a resistive load of 26·45 Ω from an AC source of 230 V, 50 Hz. Compute the firing angle to deliver 1000 W to the load. Also com…

(a) A single-phase full bridge inverter is used to produce a 50 Hz voltage across a series R-L load (R = 10 Ω and L = 20 mH) using bipolar PWM. The DC input to the bridge is 380 V…

(a) For the circuit shown below, calculate the output voltage : R₁ = 1 kΩ R₂ = 2 kΩ R₃ = 3 kΩ R₄ = 10 kΩ R₅ = 10 kΩ R₆ = 100 kΩ V₁ = -1 V V₂ = -2 V V₃ = 8 V (b) A signal xₐ(t) is…

(a) (i) What do you mean by grading of cables? What are the methods of grading? (ii) Derive the condition for minimum value of gradient at the surface of the conductor. (iii) Dete…

(a) A DC motor has an armature resistance of 0·5 Ω and Kφ of 3 Vs. The motor is driven by a single-phase thyristorized full converter. The input to the converter is an AC source o…

(a) A 20 kW, 500 V DC shunt motor (having 90% full-load efficiency) has 40% armature copper losses of its full-load losses. Calculate the resistance values of a 4-section starter…

(a) A full-controlled full-wave bridge AC/DC converter is fed from a single-phase, 230 V, 50 Hz supply, and is in turn feeding to an R-L load (R = 10 Ω and L = 100 mH). The firing…

(a) A signal is given by x[t] = cos(28πt) + 2cos(40πt) + 3cos(70πt) This signal is sampled at 90 samples/s to get discrete-time signal x(n). (i) Find the periodicity of the indivi…