The dynamic behaviour of a series RLC circuit is described by: d2vc/dt2 + dvc/dt + vc = Vsu(t) where vc is the capacitor voltage and Vs is the DC supply voltage. Find the nature of damping in the circuit.
The voltage and current through a circuit element are: v(t) = 628 sin(314t + 45°) V i(t) = 10 sin(314t − 45°) A Identify the circuit element and determine its value.
Statement 1: A system is said to be completely controllable if it is possible to transfer the system state from an initial state X(t0) to any desired state X(t) in a specified finite time by a control vector u(t).
Statement 2: A system is said to be completely observable, if every state X(t0) can be completely identified by measurement of the outputs y(t) over the time interval 0 ≤ t ≤ ∞.
In a bode magnitude plot, which one of the following slopes would be exhibited at high frequencies by a 4th order system having two zeros in left half of s-plane?
Consider the following statements about error-based performance criterion.Statement 1:Minimization of integral of squared error should be considered as design criteria when error magnitude is very small (typically lesser than 0.1).Statement 2:Minimization of integral of time-weighted absolute error should be considered as design criteria when error persists for longer time.Choose the correct options from the following:
The loop transfer function G(s)H(s) of a unity feedback system is given by G(s) H(s) = (s + 2) / ((s + 4) (s + 5) (s + 6)). How many branches of root locus will tend towards infinity?
An LTI system having transfer function G(s) = 10/(s + 5) is controlled by a proportional controller with a gain of Kp = 2. Consider the unity feedback system. Find the steady state error of the closed loop system, if the reference signal is a step input with a magnitude of 5.
Consider the following statements regarding time-domain analysis of a control system:Statement 1:Derivative control improves the system’s transient performance.Statement 2:Integral control does not improve system’s steady state performance.Choose the correct options from the following:
The open-loop transfer function of a unity-feedback control system is G(s) = K/[s(s + 1)]. If the gain K is increased to infinity, then the damping ratio of the closed-loop system will tend to become
A unity-feedback system has open-loop transfer function G(s)H(s) = 16/(s² + 4s). The steady-state response c(t) will exhibit a resonance peak at a frequency of
The open-loop transfer function of a unity-feedback system is G(s) = K(s + 2)/[s(s² + 2s + 2)]. What is the value of the centroid in the root locus for this system?
A unity-feedback second order control system is characterised by G(s) = K/(Js2 + Bs) Which of the following transient response specification will be unaffected by the variation in parameter K?
Consider the following statements in the context of state space model of a system.Statement 1:State space model is always unique for a given system.Statement 2:State space model can be derived from the transfer function.Choose the correct options from the following:
The transfer function of a closed-loop unity-feedback system is (2s² + 6s + 5)/[(s + 1)²(s + 2)]. What is the characteristic equation of the closed-loop system?
Read the following statement in the context of a DC motor position control system.Statement 1:Rate feedback is often provided to improve the damping of control system.Statement 2:The rate feedback is provided by a tachogenerator.Choose the correct option from the following:
In the context of a passive low pass filters, read the following statements.Statement 1:The highest magnitude response can be unity as input frequency reaches to infinity.Statement 2:Second order systems have steeper roll-off rate in magnitude response after cut-off frequency.Choose the correct option from the following:
Read the following statements in the context of a series R-L-C network with ideal resistor R, inductance L and capacitance C.Statement 1:The RLC network will exhibit resonance at ωr = 1/√(LC) rad/s.Statement 2:The RLC network represents a nonlinear system as L and C are nonlinear elements.Choose the correct option.
A balance star connected load with impedance of 20 ∠ 45°Ω is supplied from a balanced 3-phase, 4-wire supply with a line voltage of 173 V(rms). What will be the current (rms) in a neutral wire?
The resistance of a copper strip having rectangular cross-section of 0.2 cm2 is 2 Ω. A metal of resistivity twice that of the copper is coated on top surface of this strip with the same thickness as that of copper strip. What will be the resistance of composite strip?
Consider the following circuit shown in Fig. Q38 and read the following statements.Statement 1:The current through the capacitor can be obtained by using only source transformation without the use of superposition theorem.Statement 2:The current through the capacitor can be obtained by using superposition theorem. Fig. Q38Choose the correct option from the following:
For the circuit shown in Fig. Q40, what should be the value of load impedance to be connected across terminals ‘a’ and ‘b’, for the maximum power transfer from the circuit. Fig. Q40
Consider the circuit shown in Fig. Q46. The switch is initially closed for a long time and opens at t = 0s. What is the value of R1 and R2, if current i(t) = 2.5 + 1.5e– 4t A for t > 0s? Fig. Q46
A battery has a short-circuit current of 30 A and an open-circuit voltage of 12 V. If the battery is connected to a load resistance of 2Ω, then what will be the power delivered by the battery?
Choose the correct option. Assertion: Power MOSFET has bidirectional current handling capability. Reason: Power MOSFET has an anti-parallel body diode.
AC source of 110 Vrms, 60 Hz supplies an ideal single-phase phase-controlled half-wave rectifier that charges a battery. Assume the battery is modelled using a voltage source of 100 V with a series resistance of 2Ω Choose the correct option. Statement-1: Minimum value of control firing angle is α = 40° (approx.) Statement-2: For firing angle, α = 60°, the battery current start falling from its peak value after 30° which is measured from the angle at which current starts rising.
An ideal dc-dc buck converter has the following parameters: dc source voltage 50 V, load voltage 20 V, load current 1 A, switching frequency 20 kHz, L and C filter values 400 μH and 100 μF respectively. The correct option is Statement-1: Peak to peak ripple in inductor current is 1.5 A. Statement-2: Converter operates in discontinuous conduction mode (DCM).
In a discontinuous current conduction (DCM) operation of dc-dc converter, Statement-1: The conversion-ratio does not depend on load resistance. Statement-2: The peak ripple in inductor current is more than average inductor current.
An ideal boost converter provides an average output voltage of 30 V to a load resistance of 50Ω from a 12 V dc source. For a peak-to-peak ripple less than one percent in capacitor voltage at switching frequency of 25 kHz, the minimum value of capacitance is
A 50 Hz single-phase voltage source inverter operates with frequency modulation ratio of 38 using unipolar sinusoidal pulse width modulation scheme. The first dominant harmonic in output voltage is
A three-phase voltage source PWM inverter operates under linear modulation and is supplied using 100 V dc source. The maximum possible value of fundamental rms voltage (line-line) is
Given the following statementsStatement 1:In the 8051, the machine cycle lasts 12 clock cycles of the crystal frequency.Statement 2:The minimum number of machine cycles needed to execute an 8051 instruction is 1.Choose the correct option for the above statements
Twenty-five-foot tap rule generally referred to as the “25-ft tap rule” allows to omit overcurrent protection at the point of supply. Which of the following condition must be met under this rule?
Building automation system (BAS) is Statement-1: An example of a distributed control system. Statement-2: BAS covers computer networking of electronic devices designed to monitor and control the fire and flood safety, lighting, HVAC and humidity control and ventilation systems.
Choose correct option about the Smart Building Energy Automation (SBEA). Statement-1: It is based on development of complete building energy management system excluding battery management system. Statement-2: It manages and controls multiple-connected battery packs. It monitors the battery quantities SOC–SOH–DOD.
A room is 120 feet by 60 feet with 16 feet ceiling. A luminaire is suspended 4 feet below the ceiling and the work plane is 4 feet above the floor. The value of room cavity ratio (RCR) is
A rectangular room has a length of 10 meters and a width of 6 meters. The room is illuminated by a lighting system with a utilization factor (UF) of 0.6 and maintenance factor of 0.9. If the total luminous flux of the installed lamps is 10,000 lumens, then the Illuminance (E) on the working plane is
Room index is used for obtaining the utilization factor of light in a particular room. A rectangular room has a length of 12 meters, a width of 8 meters and a mounting height of 4 meters from the working plane. The Room Index (RI) is
As per National Electrical Code for a grounding electrode conductor, the maximum resistance of grounding electrode (single rod, pipe or plate) to earth must not exceed
Choose the correct option Statement-1: LED lights remove the need of applying relatively large amount of heat as in incandescent or fluorescent lamp to glow. Statement-2: LED lights need electronic driver. However, driver generates heat in LED lights.
Choose the correct option. Statement-1: In parallel MTDC system, the valve-voltage rating is related to the power rating. Statement-2: In series MTDC system, the valve-current rating is related to the power rating.
Choose the correct option. Statement-1: Ground impedance is negligible in DC transmission system. Statement-2: In DC transmission systems, mono-polar transmission is not possible.
The firing angle (α) of a 6-pulse three-phase line commutated converter (Graetz bridge) is 45°. The approx. value of average DC output voltage for AC line voltage of 400 kVrms is
Choose the correct option about dc-link control in HVDC system Statement-1: Current control by controlling delay angle at inverter-end while keeping minimum extinction angle at rectifier-end results in the better voltage regulation. Statement-2: Currents during line faults are automatically limited with rectifier station in current control.
Choose the correct option.Statement 1:A minimum Extinction Angle (CEA) of inverter in HVDC systems is maintained to avoid commutation failures.Statement 2:CEA control exhibits negative-resistance characteristics, making it unstable when connected to weak AC systems.Choose the correct option.
Choose the correct option. Statement-1: Voltage instability is more severe at the voltage setting terminal (VST) compared to other terminals irrespective of whether it is rectifier or inverter in HVDC system. Statement-2: Constant AC voltage control at VST improves voltage stability at all terminal including VST without any coordination.
In HVAC systems, the conditioned-space is generally classified as negative room and positive room based on the room-air pressure. The example of positive room is
Choose the correct option about Pitot tube employed in fire-fighting system. Statement-1: This is an instrument for the measurement of water velocity pressure. Statement-2: This can be used to determine approximate amount of water flowing with the help of size of opening (orifice/nozzle) and water velocity pressure.
In firefighting vertical water pump, an hydraulic turbulence can exert alternating dynamic forces on the vertical structure. Statement-1: The frequencies of these dynamic forces are independent on the speed of the pump. Statement-2: When the frequency of dynamic forces matches the natural frequency of a pump component, the resonant vibration will occur.
Choose correct option about the building management system (BMS). Statement-1: BMS is a computer-based control system that controls and monitors the mechanical and electrical equipment in buildings. Statement-2: BMS connects the building services plant back to a central computer to enable the control of on/off times of lighting systems excluding HVAC system.
Given the following statementsStatement 1:Quantity ‘work’ is not a vectorStatement 2:Displacement of a mosquito in space is not a scalar fieldChoose the correct option for the above statements
A piece of wood is described by z = 0, 30° < ϕ < 60°. Given the following statementsStatement 1:The piece of wood includes neither the x-axis nor the y-axisStatement 2:The piece of wood is infinitely longChoose the correct option for the above statements
Given the following statementsStatement 1:The curl of a vector field is another vector field.Statement 2:The divergence of the curl of a vector field is zero.Choose the correct option for the above statements
Point charges Q1 = 1 nC and Q2 = 2 nC are at a distance apart. Given the following statementsStatement 1:As the distance between them decreases, the force on Q1 increases linearly.Statement 2:The force on Q2 is the same in magnitude as that on Q1.Choose the correct option for the above statements
Given the statement, “The electric flux density on a spherical surface r = a is the same for a point charge Q located at the origin and for charge Q uniformly distributed on surface r = b (b < a).” Corresponding to this statement, choose the correct option.
For a static magnetic field, the following statements are givenStatement 1:It is solenoidal.Statement 2:It is conservative.Choose the correct option for the above statements
Out of the following, what is the major factor for determining whether a medium is free space, lossless dielectric, lossy dielectric or a good conductor?
Given the following statements:Statement 1:A periodic signal cannot be anticausal.Statement 2:An energy signal must be of finite duration.Choose the correct option for the above statements
Given the following statementsStatement 1:Convolution of an odd and an even function is an odd function.Statement 2:Convolution of two odd or two even functions is an even function.Choose the correct option for the above statements
Given the following statements for LTI systemsStatement 1:The inverse of a causal LTI system is always causal.Statement 2:If an LTI system is causal, then it is stable.Choose the correct option for the above statements
For the Laplace transform of a signal specified as (s³ − 1)/(s² + s + 1), the number of zeros located in the finite s-plane and the number of zeros located at infinity are respectively
Given the following statementsStatement 1:Addition in Boolean algebra is equivalent to the NOR function.Statement 2:“The complement of a product of variables is equal to the sum of the complements of each variable” is a statement of DeMorgan’s theorem.Choose the correct option for the above statements
Given the following statements:Statement 1:A latch has one stable state.Statement 2:A latch is considered to be in the RESET state when the Q output is low.Choose the correct option for the above statements
Given the following statements:Statement 1:The modulus of an 8-bit Johnson counter is eight.Statement 2:A ring counter uses one flip-flop for each state in its sequence.Choose the correct option for the above statements
The group of bits 10110101 is serially shifted (right-most bit first) into an 8-bit parallel output shift register with an initial state of 11100100. After two clock pulses, the register contains
Given the following statements:Statement 1:Assembly language is a high-level language.Statement 2:Assembler directives are not used by the CPU itself. They are simply a guide to the assembler.Choose the correct option for the above statements
The speed of a separately excited DC motor can be controlled by changing 1. Field current 2. Supply voltage 3. Armature resistance Select the correct option:
Consider following statements: Assertion: DC series motors are suitable for electric locomotives. Reason: DC series motors provide high starting torque. Of these statements:
A separately excited DC generator achieves maximum efficiency when terminal voltage is 220 V and induced EMF is 240 V. If the armature resistance is 0.25Ω, then what will be stray losses in the generator?
Consider the following statements: EMF induced per phase in an alternator depends on 1. Frequency 2. Number of turns per phase 3. Pitch factor 4. Distribution factor Select the correct option:
Consider the following statements: Assertion: Single-phase induction motor is not self-starting. Reason: Net rotating magnetic field produced by single-phase winding at standstill is zero. Of these statements:
A coil having 1000 turns is wound on a core. The flow of 1 A current through the coil produces 1 mWb flux in the core. What will be the energy stored in the magnetic field?
Consider the following statements: Assertion: The no-load current of an induction motor is usually more than that of a transformer of similar rating. Reason: An induction motor can be considered as a generalized transformer. Of these statements:
The per-unit impedance of a power system component is 0.25. If the base kV and base MVA are halved, then the new value of the per-unit impedance will be
Match List-I (Classification of head) with List-II (Type of turbine) in regards to hydropower plants and select the correct answer using the codes given below the lists. List-I List-II a. Low head, 2-15 m 1. Pelton b. Medium head, 16-70 m 2. Francis or Pelton c. High head, 71-500 m 3. Kaplan or Francis d. Very high head, >500 m 4. Propeller or Kaplan Codes: a b c d
Consider following statements: Assertion: When a line-to-line (L-L) fault takes place at the terminals of an open-circuited generator, the phase voltages are sometimes indeterminate though line voltages are always determinable. Reason: During L-L fault, a zero-sequence voltage is always indeterminate. Of these statements:
Why is a ring distribution system preferred to a radial system? 1. Voltage drop in the feeder is less in ring distribution system 2. Power factor is higher in ring distribution system 3. Supply is more reliable in ring distribution system Select the correct option:
The incremental costs of two generators supplying total load of 200 MW are dFA dFB = 2.0 + 0.01PA and = 1.6 + 0.02 PB dPA dPB For economical operation, the generator outputs PA, PB should be ________ respectively.
Match List-I (Equipment) with List-II (Application) and select the correct answer using the code given below the lists: List-I List-II a. Metal oxide arrester 1. Protects generator against short circuit faults b. Isolator 2. Improves transient stability c. Auto-recloser 3. Allows circuit breaker maintenance d. Differential relay 4. Provides protection against surges Codes: a b c d
Objective of energy management and audit in a business enterprise includes which of the following? 1. Minimizing cost of energy consumption 2. Minimizing the waste of energy 3. Scaling harmful impacts of pollution on health 4. Minimizing environmental degradation Select the correct option:
As per CoP26 (26th United Nations Climate Change Conference) held in Gasglow, 2021, how much % of cumulative installed capacity from non-fossil energy sources, India has committed to achieve by 2030?
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