Objective Questions UNIT-I TRANSIENT ANALYSIS (First and Second Order Circuits)

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1 Objective Questions: Objective Questions UNIT-I TRANSIENT ANALYSIS (First and Second Order Circuits) 1. The time constant of RL circuit is... a)rl b)l/r c)r/l d)l 2. Inductor does not allow sudden changes in... a)voltage b)power c)current d)all of the above 3. Transient current in an RLC circuit is oscillatory when... a)(r/2l) 2 >1/LC b) (R/2L) 2 >1/LR c) (R/2L) 2 <1/LC d)(r/2l) 2 =1/LC 4.The time constant of RC circuit is... a)rc b)c/r c)r/c d)r 5. When a series RL circuit is connected to a voltage V at t=0, the current passing through the inductor L at t=0+ is... a)0 b)infinity c)1 d)v 6. Capacitor does not allow sudden changes in... a) voltage b)power c)current d)all of the above 7.The laplace transform of a unit step function is... a)1 b)1/s c)s d)0 8. The laplace transform of a impulse function is... a) 1 b)1/s c)s d)0 9. The final value theorem is used to find the...\ a)transient value b)steady state value c)total response d)natural response 10.When a series RC circuit is connected to a voltage V at t=0, the current passing through the circuit at t=0+ is... a) 0 b) infinity c)1 d)v/r 11. The transient current in a loss free L-C Circuit when excited from an ac source is an sine wave a) undamped b) over damped c)under damped d) critically damped 12. The transient response occurs a)only in resistive circuits b) only in inductive circuits c) only in capacitive circuits d) both options b and c 13.Transient behavior occurs in any circuit when a) there are sudden changes of applied voltage b) the voltage source is shorted

2 c)the circuit is connected or disconnected from the supply 14. Laplace transform analysis gives d)all of these a) time domain response only b) frequency domain response only c) both a &b d) none 15.The laplace transform of first derivative of a function f(t) is a) F(s)/s b) sf(s)-f(0) c) F(s)-f(0) d)f(0) 16. The laplace transform of integral of a function f(t) is a) F(s)/s b) sf(s)-f(0) c) F(s)-f(0) d)f(0) 17. A 10 Ω resistor, a 1 H inductor and 1 µf capacitor are connected in parallel. The combination is driven by a unit step current. Under the steady state condition, the source current flows through. (a) the resistor (b) the inductor (c) the capacitor only (d) all the three elements 18. The Steady state value can be calculated using...\ a) initial value b)final value theorem c)total response d)natural response 19. Sudden change in current is not occurred in which component a) capacitor b)inductor c)resistor d)natural response 20. Sudden change in voltage is not occurred in which component a) capacitor b)inductor c)resistor d)natural response Objective Questions UNIT-II TWO PORT NETWORKS 1. Which of the following parameters do not exist for the two port network shown in fig. a)abcd b) Y c) h d) Z 2.Find the Z parameters of the following

3 a)1,1,1,1 b) 1,2,2,1 c) do not possible d) none. 3.Find the Z parameters of Fig 3. a)1k,0,0,1k b)1k,1k,1k,1k c)0,1,2,1 d) 1k,2,2,1.k 4. For a two port reciprocal network z 12 = a)z 11 b) Z 21 c) Z 22 d) none 5. Two port networks are cascaded. The combination is to be represented as a single two-port network. The parameters of the network are. a) Z-parameter matrix b) Y-parameter matrix c) h-parameter matrix d) ABCD-parameter matrix 6. For a two port network to be reciprocal a) Z 11 =Z 22 b) Y 12 = Y 21 c) h 22 = h 12 + h 21 d) AD - BC=0 7. Two two port networks are parallel connected. The combination is to be represented as a single twoport network. The parameters of the network are. a) Z-parameter matrix b) Y-parameter matrix c) h-parameter matrix d)abcd-parameter matrix 9. A two port device is defined by the following pair of equations I 1 = 2V 1 + V 2 and I 2 = V 1 + V 2 the impedance parameters (Y 11,Y 12,Y 21,Y 22 ) are given by a)(2,1,1,1) b) (1,-1,-1,2) c) (1,1,1,2) d) (2,-1,-1,1) 10. The short circuit admittance matrix of a two-port network is, The two port network is a) Non-reciprocal and passive b) Non-reciprocal and active c) Reciprocal and passive d) Reciprocal and active 11. z-parameters is also known as open-circuit parameters 12. y-parameters is also known as short-circuit parameters 13. ABCD parameters is also known as Transmission parameters 14. When 2 two port networks are connected in series we use z-parameters

4 15. When 2 two port networks are connected in parallel we use y-parameters 16. When 2 two port networks are connected in cascading we use ABCD-parameters 17. For a two port network to be symmetrical Z 11 =Z For a two port network to be reciprocal is AD-BC=1 19. For a two port network to be reciprocal is Y 12 =Y For a two port network to be symmetric is A=D FILTERS Objective Questions UNIT-III FILTERS & ATTENUATORS 1. The basic type of filter is _ a) m-derived Filter b) Constant-k Filter c) a and b d) none 2. Z 1 Z 2 = _ a)k 2 b) K c) m d) none 3. Filter elements are only a. a)capacitors and Resisters b) Resisters and Inductors c) Capacitors and Inductors d) none 4. Attenuation constant and phase shift constants in Stop band are a. a) increases gradually and constant b) both increases gradually b. c) both zero d) zero and increases gradually 5. The range m values lies between a. a) 1 to10 b) -1 to 1 c) 0 to 1000 d) 0 to 1 6. Attenuation constant and phase shift constants in Pass band are a. a) increases gradually and zero b) both increases gradually b. c) both zero d) zero and increases gradually 7. Band Pass filter is _. a. High Pass Filter followed by Low Pass Filter b) Low Pass Filter followed by High Pass Filter c) not possible d)none. 8. Series L and C Circuit provides _ impedance at resonance. a) b) - c) 0 d)none 9. Series R,L and C Circuit provides _ impedance at resonance. a) b) - c) 0 d)r 10. m- derived low pass filter consists of a. Two inductors & two capacitors c) Three inductors & one capacitor b. One inductor & three capacitors d)four inductors 11. Application of attenuator is To provide Attenuation 12. R 1 in T type attenuator is R o (N + 1) / (N - 1)

5 13. R 2 in π Attenuator is R o 2N / (N 2-1) 14. R 1 in π Attenuator is R o (N + 1) / (N - 1) 15. R 2 in T Attenuator is R o (N - 1) / (N + 1) 16. R 2 in lattice Attenuator is R o (N + 1) / (N - 1) 17. R 2 in lattice Attenuator is R o (N + 1) / (N - 1) 18. R A in Bridged T Attenuator is R o 2N / (N 2-1) 19. R B in Bridged T Attenuator is R o (N - 1) / (N 2-1) 20. A fixed attenuator with constant attenuation is called as pad UNIT-IV (D.C MACHINES) 1. The purpose of providing the starter is used to reduce the starting current 2. If a load on a dc shunt motor is increased by its speed is decreased primarily by decrease in back emf 3. Which motor is known as constant speed motor is shunt motor 4. If a pole flux of a dc motor approaches zero its speed approaches will approach infinity 5. As load of the dc motor increases its speed decreases 6. 2 In case of a dc series motor the torque is proportional to I a 7. In case of a dc shunt motor the torque is proportional to I a 8. The direction of torque is determined by Flemings left hand rule 9. The counter emf of a dc generator will help in energy conversion 10. Voltage equation of dc motor is V=E b +I a Ra 11. In a commutator mica material is used 12. In which of the following dc generator residual magnetic flux is not required for emf generation is separately excited 13. Core laminations are generally made up of silicon steel 14. The direction of induced emf is determined by Flemings right hand rule 15. In a lap wound of a d.c generator if no. of poles are doubled, then generated emf will become remain same 16. In a wave wound of a d.c generator if no. of poles are doubled, then generated emf will become double 17. In a dc generator if P is no. of poles and N is rpm of rotor,then frequency of magnetic reversals is NP/ Mechanical Energy Converted to Electrical energy in case of Generator 19. The direction of induced e.m.f and hence current in a conductor can be determined by Fleming s Right hand rule 20. In DC Machine which Induced e.m.f is suitable dynamically induced e.m.f 21. Brushes are made up of Carbon 22. Armature Reaction is related to (A)Main flux &Armature flux (B) only Main flux (C) only Armature flux None

6 23. Which is suitable for Electric Traction? (A)Series Motor (B) Shunt Motor (C) Compound Motor (D) Dc Generator 24. The Basic Principle in dc generator is (A)Electro Magnetic Induction (B) Flemings Left hand rule (C) Law of conservation Energy 25. EMF generator in the armature of dc generator is A.C 26. The component used to convert A.C to d.c voltage in a d.c generator is Commutator UNIT-V (TRANSFORMERS) 1. Which loss depends on thickness of lamination is eddy current 2. Hysteresis loss is minimized by using the material of hysteresis coefficient 3. In ideal transformer is no loss takes place 4. Eddy current losses are minimized by laminating the core 5. E.M.F of a transformer is 4.44FNф m 6. E.M.F of transformer will not depend on the following factor is Power 7. Transformer action requires alternating magnetic flux 8. The basic function of a transformer is to change the level of voltage 9. In a two winding of a transformer the emf per turn in a secondary winding is always equal to the induced emf per turn in primary 10. If the supply frequency of a transformer is increased, keeping supply voltage is constant then Both magnetizing and core loss component of current will decrease 11. For a transformer.n 1 =1000,N 2 =1500,E 2 =300V then E 1 =200V 12. Comparing to secondary of a loaded step up transformer, the primary has lower voltage and higher current 13. A step down transformer decreases voltage 14. A step up transformer decreases current 15. The primary and secondary induced emf E 1 and E 2 in a two way winding transformer is always in phase with each other 16. In an ideal transformer, the no load current I o is lags behind V 1 by Which loss is not common between a transformer and rotating machines is Winding loss 18. Magnetizing current of a transformer is given by I o sinф 19. The voltage transformation ratio is equal to the ratio of secondary emf to primary emf 20. In a ideal transformer winding resistance is zero 21. An ideal transformer is one in which has no losses and magnetic leakage 22. In a transformer the energy is converted from primary to secondary by the flux 23. Induced e.m.f in a coil is directly proportional to Rate of change of flux linkage 24. The transformer rating is KVA 25. The transformer transforms Voltage & Current 26. The Primary and Secondary induced E.M.Fs E1 & E2 in a Two winding transformer are always Anti-Phase with each other 27. The Step-up transformer increases Voltage

7 28. The Step-down transformer decreases Voltage 29. The main purpose of performing O.C test on a transformer is to measure Iron losses 30. The main purpose of performing short circuit test on a transformer is to measure Copper losses

No. of Printed Pages : 5 ADVANCED LEVEL CERTIFICATE COURSE IN ELECTRICAL ENGINEERING / DIPLOMA IN ELECTRICAL ENGINEERING / ACELVI / DELVI

No. of Printed Pages : 5 ADVANCED LEVEL CERTIFICATE COURSE IN ELECTRICAL ENGINEERING / DIPLOMA IN ELECTRICAL ENGINEERING / ACELVI / DELVI No. of Printed Pages : 5 BIEE-027 ADVANCED LEVEL CERTIFICATE COURSE IN ELECTRICAL ENGINEERING / DIPLOMA IN ELECTRICAL ENGINEERING / ACELVI / DELVI 00969 Term-End Examination June, 2012 BIEE-027 : ELECTRICAL