Description : Determine the correctness or otherwise of the following Assertion [a] and the Reason [r]. Assertion: Fast decoupled load flow method gives approximate load flow solution because it uses several assumptions. Reason: Accuracy ... the correct reason for [a]. c) [a] is false and [r] is true.
Last Answer : c) [a] is false and [r] is true
Description : Mention any three advantages of N-R method over G-S method.
Last Answer : • The N-R method has quadratic convergence characteristic and so convergence faster than G-S method. • The number of iterations for convergence is independent of the size of the system in N-R method. • In N-R method the convergence is not affected by the choice of slack bus.
Description : A power system has 100 buses including 10 generator buses. For the load flow analysis using Newton-Raphson method in polar coordinates, the size of the Jacobian is a) 189x189 b) 100x100 c) 90x90 d) 180x180
Last Answer : a) 189x189
Description : A 10-bus power system consists of four generator buses indexed as G1, G2, G3, G4 and six load buses indexed as L2, L2, L3, L4, L5, L6. The generator-bus G1 is connected ... of non linear equations required for solving the load flow problem using Newton-Raphson method in popular form is________.
Last Answer : 14
Description : In a load flow problem solved by newton-Raphson method with polar coordinates, the size of the Jactobian is 100 × 100. If there are 20 PV buses in addition to PQ buses and a slack bus, the total number of buses in the system is_____
Last Answer : 61
Description : In a load flow analysis of a power system, the load connected at a bus is represented as a) Constant current drawn from the bus b) Constant impedance connected at the bus c) Voltage and frequency dependent sources at the boss d) Constant real and reactive power drawn from the bus
Last Answer : d) Constant real and reactive power drawn from the bus
Description : In load flow studies of a power system, a voltage control bus is specified by a) Real power and reactive power b) Reactive power and voltage magnitude c) Voltage and voltage phase angle d) Real power and voltage magnitude
Last Answer : d) Real power and voltage magnitude
Description : Advantage of Gauss-Seidel method is a) applicable for large power system network b) calculation time for each iteration is less c) number of iterations are less d) all of the above
Last Answer : b) calculation time for each iteration is less
Description : What technique is used to solve load flow problems using Z-bus (Bus impedance matrix)?
Last Answer : The formulation of load flow problem using Zbus employs Diakoptics techniques which is actually the piecewise solution of the power system problem by using tearing off technique.
Description : Discuss the effect of acceleration factor in the load flow solution algorithm.
Last Answer : An acceleration factor is a value that can be used to speed up the convergence and reduce the number of required alteration in a Gauss Seidel method of power flow analysis .Very high or very ... trial and error load flow analysis. A generally recommended value of the acceleration factor is 1.6.
Description : What is the need for load flow analysis.
Last Answer : The load flow study of a power system is essential to decide the best operation of existing system and for planning the future expansion of the system. It is also essential for designing a new power system.
Description : What is the information that are obtained from a load flow study.
Last Answer : • The magnitude and phase of bus voltages, real and reactive power flowing in each line and the line losses. • The load flow solution also gives the initial conditions of the system when the transient behavior of the system is to be studied.
Description : Which of the following matrix is used for load flow studies? a) null matrix b) Unit matrix c) Z bus matrix d) Y bus matrix
Last Answer : d) Y bus matrix
Description : For load flow studies, what are the quantities specified at load bus are. a) P and V b) P and Q c) V and δ d) δ and Q
Last Answer : b) P and Q
Description : In power system, if a voltage controlled bus is treated as a load bus then which one of the following limits would be violated? a) Voltage b) Active power c) reactive power d) Phase angle
Last Answer : a) Voltage
Description : In power system, the maximum number of buses are a) Generator buses b) Load buses c) Slack buses d) P-V buses
Last Answer : b) Load buses
Description : What is the need for slack bus in power flow analysis.
Last Answer : The slack/swing bus is needed to account for transmission line losses. In a power system the total power generated will be equal to sum of power consumed by loads and losses. In a power ... power are not specified for slack bus. They are estimated through the solution of load flow equations.
Description : For n bus power system size of Y bus matrix is a) n*n b) (n-1)*(n-1) c) (n-1)*(n-2) d) (n-2)*(n-2)
Last Answer : a) n*n
Description : Define voltage-controlled bus and load bus.
Last Answer : LOAD BUS A bus is called PQ bus or load bus when real and reactive components of power are specified for the bus. In a load bus the voltage is allowed to vary within permissible limits ... constant using automatic voltage regulator, we can specify constant PGi and | Vi | for these buses.
Description : When will the generator bus is treated as load bus.
Last Answer : If the reactive power of a generator bus violates the specified limits then the generator bus is treated as load bus.
Description : Specified quantities of load bus are a) P and Q b) V and δ c) P and δ d) Q and V
Last Answer : a) P and Q
Description : What are the advantages of FDLF method.
Last Answer : FDLF method is faster, simple to program, more reliable and requires less memory than NR load flow method. FDLF method requires more iteration than N-R method, but requires less time per iteration.
Description : What are the disadvantages of NR method.
Last Answer : • The programming is more complex. • The memory requirement is more. • Computational time per iteration is higher due to large number of calculations per iteration.
Description : Mention the various types of buses in power system with specified quantities for each bus.
Last Answer : • Load bus or PQ-bus (P and Q are specified- Voltage magnitude and angle are to be obtained) • Generator bus or voltage controlled bus or PV bus (P and V are specified- Voltage angle and Q are to be obtained)
Description : A 1000 × 1000 bus admittance matrix for an electric power system has 8000 non-zero elements. The minimum number of branches (transmission lines and transformers) in this system are _____ (up to 2 decimal places)
Last Answer : Ans: 3500.00
Description : The voltage of a particular bus can be controlled by controlling the a) Active power of the bus b) Reactive power of the bus c) Phase angle d) All of the above
Last Answer : b) Reactive power of the bus
Description : A 4 bus power system consists of 4 transmission lines, then find the sparsity of Y bus matrix? a) 0.75 b) 0.25 c) 0.4 d) 0.5
Last Answer : b) 0.25
Description : Explain Flat Voltage start.
Last Answer : In iterative methods of load flow solution, the initial voltages of all buses except slack bus are assumed as 1+j0 p.u. This is referred to as flat voltage start.
Description : What is jacobian matrix?
Last Answer : The Jacobian matrix gives the linearized relationship between small changes in voltage angle or voltage magnitude with a small changes in real and reactive power.
Description : What are the four quantities that are associated with each bus in a system?
Last Answer : • Real Power • Reactive Power • Voltage magnitude • Phase angle of voltage
Description : In a 4 bus,4×4 Y bus matrix the number of non zero elements are 12. Find the number of transmission lines? a) 8 b) 4 c) 2 d) 5
Last Answer : b) 4
Description : Which of the following quantities are to be calculated for generator bus a) P and V b) V and δ c) δ and Q d) Q and P
Last Answer : c) δ and Q
Description : The value of off diagonal elements is a) sum of admittances connected at bus j b) which is connected between bus i and bus j with positive sign c) which is connected between bus i and bus j with negative sign d) sum of admittances connected at bus i
Last Answer : c) which is connected between bus i and bus j with negative sign
Description : If sparsity of a 5 bus transmission line is 0.4. Find the number of transmission lines? a) 6 b) 5 c) 4 d) 3
Last Answer : b) 5
Description : A network containing 50 buses in which 10 are the voltage control buses, 6 are the generator buses. Find the size of the Jacobian matrix. a) 84*84 b) 83*83 c) 34*34 d) 33*33
Last Answer : b) 83*83
Description : um of the elements of row i equal to shunt admittances connected to bus i. If this summation is zero, indicates there is no a) shunt admittance b) mutual coupling c) both 1 and 2 d) none of the above
Last Answer : c) both 1 and 2
Description : Normally Z bus matrix is a a) null matrix b) sparse matrix c) full matrix d) unit matrix
Last Answer : full matrix
Description : Which of these helps scientists to make accurate calculations?
Last Answer : technology
Description : What of these helps scientist to make accurate calculations?
Last Answer : What is the answer ?
Description : All of the following statements are incorrect except: A. Precision and accuracy should go side by side in a scientific work (Answer) B. Scientific work must be precise, accuracy is not ... work must be accurate, precision is not essential D. Calculations must be made before any experiment
Last Answer : A. Precision and accuracy should go side by side in a scientific work (Answer)
Description : Were all quarks, leptons and gluons quantum entangled by the Big Bang? If so, what decoupled them?
Last Answer : Ah, at last one of your questions I can answer Spontaneous combustion
Description : what dealing with very small or very large numbers, what steps would you take to improve the accuracy of the calculations?
Last Answer : the luxury hybrid mattress combining the best of latex, memory foam, tufting and coil technology to provide the best sleep money can buy.
Description : Design calculation for multiple component distillation is done by (A) Ponchon-Savarit method (B) McCabe-Thiele method (C) Enthalpy concentration method (D) Tray to tray calculations
Last Answer : (D) Tray to tray calculations
Description : Which of the following methods of depreciation calculations results in book values greater than those obtained with straight line method? (A) Multiple straight line method (B) Sinking fund method (C) Declining balance method (D) Sum of the years digit method
Last Answer : (B) Sinking fund method
Description : 47. The method of formal calculations often termed as Linear Programming was developed later in which year? a. 1947 b. 1988 c. 1957 d. 1944
Last Answer : a. 1947
Description : Pick out the wrong statement. (A) The integral method of analysing kinetic data is used when the data is scattered (B) The differential method of analysing kinetic data requires more accurate ... less than one for identical feed composition, flow rate, conversion and for all positive reaction orders
Last Answer : (C) When the reaction rate is independent of temperature, the reaction is said to be of zero order
Description : Direct method of contouring is (A) A quick method (B) Adopted for large surveys only (C) Most accurate method (D) Suitable for hilly terrains
Last Answer : (C) Most accurate method
Description : Which of the following are the components of loamy soils? 1. Red soil 2. Clay soil 3. Alluvial soil 4. Silt soil 5. Sandy soil In d i a n So i l , Se a s o n s a n d N a t u r a l Ve g e t a t i o n (a) I and II (b) I, III and IV (c) II and V (d) II, III and V
Last Answer : Ans: (c)
Description : Who was the first speaker of the LokSabha : (1) Dr. S.P. Mukerjee (2) G.V. Mavalankar (3) N. Sanjeev Reddy (4) B.R. Ambedkar
Last Answer : (2) G.V. Mavalankar Explanation: Ganesh Vasudev Mavalankar was, on 15 May 1952, elected the first Speaker of the Lok Sabha after the first general elections in independent India. Earlier, he ... 1946 to 1947) of the Central Legislative Assembly and then Speaker of the Constituent Assembly of India.
Description : Which one of the following applications software’s is used to obtain an accurate root locus for? a) LISP b) MATLAB c) dBase d) Oracle Ans: B 6.Lenz devised a rule to find out direction of a)current induced in a circuit b)electromagneticdifference c)potential difference d)flow of power in fuse
Last Answer : Ans: A