AP PGECET- 2016(Electrical Engineering)

If λ is an eigen value of A, the the eigen value of adjoint of A is

If u = x(1-y), v = xy, then δ(u, v)/ δ(x, y) =

The real and imaginary parts of a complex analytic function are

If r_yx and r_xy are the regression coefficients of y on x and x on y then the coefficient of correlation is

At very high temperatures, extrinsic semiconductor becomes intrinsic semiconductor because

If a bias voltage of V_t (in Volts) is applied to a forward biased silicon P-N junction diode with a non ideality coefficient of 2, the diode current (in Amps) shall be

The threshold voltage of an n- channel enhancement mode MOSFET is 0.5V when the device is biased at a gate voltage of 3V. Pinch off would be occurs at a drain voltage of

If CS = A₁₅A₁₄A₁₅,A₁₂ (and its value is 0111) is used as the chip select logic of A 4K RAM in an 8085 system then its memory range will be

Which of the following instructions is not available in 8085 microprocessor?

Assertion (A) : Wein bridge oscillator is generally used as a variable audio frequency oscillator

Reason (R) : by using either capacitor (or) resistor in one of the arms of the bridge, the frequency of a wein bridge oscillator can be varied

The internal resistances of an ideal current source, and an ideal voltage source are, respectively,

The equation i(0 +) = i(0 – ) = some finite value,  where the notations and symbols have usual meanings (as adopted in transient response analysis of circuits ) holds good in the case of

A series R-C circuit has constant value of R and varying value of C. The current locus with constant applied voltage V at constant frequency, as C is varied, is a semi circle with centre at

The current through a linear time-invariant inductor with inductance L = 10^-3 is given by i_L = 0.1 sin 10⁶ t. The voltage across the inductor is

Which of the following are known as the short circuit parameters of a 2- port network?

The line current in a balanced delta system is 30 A. The load current is

Possible maximum value of mutual inductance between two coils of self inductances, L₁ and L₂ is

The resistance required for critical damping in a series RLC circuit is

The impedance of a series resonant circuit, at half power frequencies, is

The magnetic field intensity at the centre of a current carrying coil of diameter d m is H). The current flowing in the coil is

Two infinite plane sheets of charge with densities of +σ and – σ C/m² are placed parallel to each other with a separating distance of d metres. The value of electric field intensity at a point exactly midway between the plane sheets is

Which of the following statements is not characteristic of a static magnetic field?

Integration of step signal gives

The period of the function Cos (π/10) (t – 3) is

If  f(t) = -f(-t), and f(t) satisfies Dirichlet’s conditions, then f(t) can be expanded in a Fourier series containing

Minimum sampling rate required to avoid aliasing when the signal 10 Cos 400 πt is sampled is

The Fourier transform of f(t) is F(ω). Then, the Fourier transform of f(at), where a is a constant is given by

Laplace transform of Cos t is

The continuous time signal sin 25 πt + sin 80 πt requires a Nyquist rate of

Consider the following systems :

1. a normal human being walking on the road, and
2. servomechanism.

Systems (i) and (ii) are, respectively,

The transfer function of a system is 10/ s(s+1)(s² + 3s + 2). The steady state errors exhibited by the system, to (i) step, (ii) ramp, and (iii) parabolic input are, respectively.

System 1 : The first column of the RH array consists of the terms 6,3,9,-2, and 4.
System 2 : The first column of the RH array consists of the terms 3,6,9,2, and -4.

The number of unstable poles for system1, and system 2, are respectively,

A second order system shows 100% overshoot in its unit step response. It can be categorized as

A unity negative feedback control system is found to have a gain margin of 20 dB. The Nyquist plot of the system

A certain control system has to open loop transfer function given by 10(s+3)(s+5)/ s(s+7)(s+9). Which portions of the real axis, among the ones given below, are parts of the root locus?

The open loop transfer function of a unity negative feedback control system is 10/ s²(7s+1). The TYPE number and order of the closed loop system are, respectively

The transfer function of a system is given by 1/ (1+T₁s)(1+T₂s). A controller of the form K(1+T₂s)/(1+T₄s) is used to improve the performance of the system when operated in closed loop with unity feedback. The rise time in the unit step response can be reduced by choosing

In the state variable representation of systems, let A denote the system characteristic matrix, and let Ø(t) denote the state transition matrix. Then, which of the following is not a property of the state transition matrix?

Observability of a system is essential for

Time constant of a first order system is defined as the time taken to reach x% of the final steady state value in the step response. The value of x is

In Torque-Voltage analogy, the Moment of Inertia of a mechanical rotational system is analogous to

The bridge most suited for accurate measurement of relative permittivity of dielectric materials is

The operation of a ramp type Digital Voltmeter is based on the principle of

The vertical deflection of an electron beam on the screen of a CRO is measured to be 8 mm. Now, the potential difference between the Y-plates is doubled, and simultaneously the pre-accelerating anode voltage is reduced to half of its previous value. Then, the vertical deflection of the beam on the screen would become

Gross errors occur in measurements because of

An induction type energy meter is found to run fast. Correction for this error can be made by

Standardization of potentiometers is done so that

The meter which does not have any component in it to provide control torque is

In a single-phase transformer, the magnetizing current is

A 230 V/460 V single-phase transformer operating at 20 A and unity power factor has primary referred resistance of 0.2 Ω and reactance of 0.5 Ω. The approximate primary induced emf is

A transformer at 25 Hz develops 20 W hysteresis loss and 50 W eddy current loss. If the applied voltage and frequency are doubled, the new core losses are

A 3-phase transformer possible 3-phase connection by a combination of star (Y or y) and delta (D or d) with 30º lead phase displacement corresponding to watch clock-face hour is

Two transformers of voltage ratio 1 kV/500 V, with impedances z₁ = j0.04 Ω and z₂ = j0.06 Ω, respectively, connected in parallel share a total load of 200 kVA. The kVA carried by each transformer is

A two winding transformer is connected as an auto-transformer with the same voltage ratio of 2:1. If primary and secondary winding resistances of auto-transformer are 0.03 Ω and 0.02 Ω, respectively, the primary equivalent resistance of auto-transformer is

In a duplex lap winding, if y_b and y_f are back-pitch and front-pitch, respectively, then

In a 4-pole wave winding connected dc motor, the cross-magnetizing AT/pole for a brush shift of θ radians

The magnetic neutral plane shifts in a dc machine

The terminal characteristics of a dc generator suitable for electric welders is

A 220 V separately excited motor with Ra = 0.5 Ω running at 500 rpm draws a current of 20 A. The value of additional resistance in armature circuit to reduce the speed to 300 rpm at constant flux is

The mechanical power developed by a 3-phase induction motor if the total rotor I²R losses are 200 W and the slip is 4 %

Slot harmonics are reduced in induction motors by using

The armature reaction in a synchronous generator supplying leading power factor load is

Torque angle for the synchronous machine is the angle between

The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu from a lagging load are 45º and 15º, respectively. The direct axis and quadrature axis currents, respectively, are

The maximum reluctance power of a salient-pole synchronous motor having direct-axis reactance, 1.0 pu and quadrature-axis reactance, 0.5 pu, and input voltage, 1.0 pu is

In a single-phase induction motor when the rotor is stationary and voltage is applied to the stator, then

In a split-phase induction motor, the resistance/reactance ratios of windings are such that

Two synchronous generators operating in parallel supply a common load of 2.5 MW. The frequency-power characteristics have a common slope of 1 MW/Hz and the no-load frequencies of the generators are 51.5 Hz and 51.0 Hz, respectively. Then the system frequency is

The speed of a 2-pole, 3-phase stepper motor operated by 1200 pulses/min

If the constants, A = D = 1 + YZ/2 of a transmission line by nominal π model, then the constants B and C, respectively are

In a per unit system of a transmission line

The insulation resistance per metre length of a single core cable of conductor radius, r, sheath inside radius, R and resistivity, ρ is

A single core lead sheathed cable with two dielectrics of permittivity 4 and 3, respectively, are subjected to same maximum stress. If the conductor diameter is 1.5 cm, the outer diameter of the first dielectric is

In a large power system for n x n matrix, the sparsity is defined as

If non-linear loads are connected to the power system, then

The benefit of power factor correction in a power system is

The power flow problem mathematical model for a linear transmission network

The sequence components of current of a single-phase load connected to a 3-phase system are

In a 3-phase balanced neutral grounded star-connected load, phase b is open. If I_a =10∠0^o  and I_c  =10∠120^o then

The value of capacitor used for power factor improvement in a feeder with V volts at 50 Hz and capacitor current I_c, is

A double-line-to-ground fault from phase b to phase c occurs through the fault impedance, Z_F to ground. The fault conditions are

A solid state relay

In the induction type directional over current relay, when a short-circuit occurs in the circuit

In a differential protection scheme of a generator winding with a fault, the secondary currents of CTs are Is1 = 2.2 + j 0 A and Is2 = 1.8 + j 0 A. The % bias setting, K of the relay is

In voltage source converter based HVDC transmission system the active power is controlled by changing

A Unified Power Flow Controller (FACTS controller) is a voltage source converter based

An SCR without any external connections is considered as

The device which allows reverse power flow and withstands highest switch frequency is

In a 230 V, 50 Hz single-phase SCR bridge converter operating at a firing delay angle, α and with large R-L load, the input source current is

In a dc-dc step-down converter, the minimum inductance required for continuous current operation, if D, f, and R are duty ratio, switching frequency and load resistance, respectively, then

If D is the duty ratio of a dc-dc step-up converter, the relation between the input and out currents is

A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc current. If the source inductance is 3 mH, the drop in dc output voltage is

The direction of rotation of an inverter fed 3-phase ac motor is reversed by

The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a firing delay angle, α and flux, ф

The PWM pulses for the gate control circuit of an IGBT inverter fed 3-phase induction motor drive are generated by using a triangular wave of frequency, f_c and

In electric traction for a trapezoidal speed-time curve, the time period is

Specific energy consumption of an electric train is the ratio between