Consider the following statements : 

1. Salient pole alternators have small diameters and large axial lengths. 

2. Cylindrical rotor alternators have a distributed winding. 

3. Cylindrical rotor alternators are wound for large number of poles. 

4. Salient pole alternators run at speeds slower than cylindrical rotor machines. 

Which of the above statements are correct ? 

(a) 1 and 3 only (b) 2 and 4 only (c) 1 and 4 only (d) 2 and 3 only

1 Answer

Answer :

Consider the following statements : 

1. Salient pole alternators have small diameters and large axial lengths. 

2. Cylindrical rotor alternators have a distributed winding. 

3. Cylindrical rotor alternators are wound for large number of poles. 

4. Salient pole alternators run at speeds slower than cylindrical rotor machines. 

Which of the above statements are correct ? 

(a) 1 and 3 only (b) 2 and 4 only (c) 1 and 4 only (d) 2 and 3 only

Related questions

Description : Salient-pole rotors may be used in alternators driven by what types of prime movers?

Last Answer : Internal combustion engines, water force and electric motors

Description : Two wires A and B of the same material have their lengths in the ratio `1 : 5` and diameters in the ratio ` 3 : 2`. If the resistance of the wire B is

Last Answer : Two wires A and B of the same material have their lengths in the ratio `1 : 5` and diameters in ... `180 Omega`, find the resistance of the wire A.

Description : Which ofthe following methods is used for air cooling of turbo-alternators ? (a) One sided axial ventilation (b) Two sided axial ventilation (c) Multiple inlet system (d) All ofthe above

Last Answer : (d) All ofthe above

Description : Which of the following types of DC motors has its field connected in parallel with its armature? A. Counter EMF B. Shunt C. Salient pole D. Series

Last Answer : Answer: B

Description : What type of rotor is used in split-phase motors? A. Drum B. Salient pole C. Squirrel-cage D. Wound-rotor

Last Answer : Answer: C

Description : What are the prime movers used for a) Salient pole alternator, b) Non- salient pole alternator.

Last Answer : The prime movers used for salient pole alternators are water wheels likeKaplan turbine, Francis turbine, Pelton wheel etc., and diesel or petrol engines. The prime movers used for non-salient pole alternators are steam turbines and gas turbines.

Description : What are the advantages of salient pole type of construction used for synchronous machines?

Last Answer : 1. They allow better ventilation. 2 The pole faces are so shaped radial air gap length increases from the pole center to the pole tips so that flux distribution in the air gap is ... 3 Due the variable reluctance, the machine develops additional reluctance power, which is independent of excitation.

Description : In a salient pole synchronous machine (usual symbols are used): (A) xq > xd (B) xq = xd (C) xq < xd (D) 0

Last Answer : Ans: C Since reluctance on the q axis is higher, owing to the larger air gap, hence xq < xd

Description : If the field circuits of an unloaded salient pole synchronous motor gets suddenly open circuited, then (A) The motor stops. (B) It continues to run at the same speed. (C) Its runs at the slower speed. (D) It runs at a very high speed.

Last Answer : Ans: B The motor continues to run at the same speed because synchronous motor speed does not depend upon load, Nα f.

Description : A salient pole synchronous motor is running at no load. Its field current is switched off. The motor will (A) come to stop. (B) continue to run at synchronous speed. (C) continue to run at ... more than the synchronous speed. (D) continue to run at a speed slightly less than the synchronous speed.

Last Answer : (B) continue to run at synchronous speed.

Description : A three phase, salient pole synchronous motor is connected to an infinite bus. It is operated at no load a normal excitation. The field excitation of the motor is first reduced to zero ... First increases and then decreases steeply (C) First decreases and then increases steeply (D) Remains constant

Last Answer : B

Description : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole)  (A) has q -axis current only (B) has d -axis current only (C) has both d and q axis currents (D) cannot be divided between q and d axis currents

Last Answer : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole) has d -axis current only

Description : Slip test is performed to determine :  (A) Slip in an induction motor  (B) Xd and Xq in a salient pole alternator  (C) Synchronous impedance in an alternator  (D) Positive and negative sequence impedances of an alternator

Last Answer : Slip test is performed to determine :  Xd and Xq in a salient pole alternator 

Description : 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 (A) 0.25 pu (B) 0.5 pu (C) 1.0 pu (D) 1.5 pu

Last Answer : 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 0.5 pu

Description : 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 (A) 0.5 pu ... pu, 0.5 pu (C) 0.707 pu, 0.707 pu (D) 0.5 pu, 0.5 pu

Last Answer : 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 0.866 pu, 0.5 pu

Last Answer : If the field winding of an unloaded salient pole synchronous motor is open circuited, the motor will stop.

Description : Salient pole rotor is use for which speed?

Last Answer : Salient pole rotor is use for low and medium speed prime movers.

Description : what will happen when excitation of an unloaded salient pole synchronous motor suddenly gets disconnected?

Last Answer : When excitation of an unloaded salient pole synchronous motor suddenly gets disconnected the motor will stop.

Description : Most large alternators have a small dc generator built into them. What is its purpose?

Last Answer : To provide dc current for the rotating field.

Description : The representation of general topography of a very flat terrain is possible only (A) By drawing contours at large interval (B) By drawing contours at small interval (C) By giving spot levels at large interval (D) By giving spot levels to salient features at close interval

Last Answer : (D) By giving spot levels to salient features at close interval

Description : Consider the following salient points in a stress-strain curve of a mild steel bar: 1. Yield point 2. Braking point 3. Yield plateau 4 . Proportionality limit 5. Ultimate point The correct sequence in which they occur while testing the mild ... , 5 and 2 (c) 4, 1, 3, 5 and 2 (d) 1, 4, 2, 3 and 5

Last Answer : (c) 4, 1, 3, 5 and 2

Description : A packed tower compared to a plate tower for a particular mass transfer operation (A) Incurs smaller pressure drop (B) Allows installation of cooling coils (C) Is less costly when built in large sizes/diameters (D) Is more suitable, if suspended solids are present in fluid stream

Last Answer : (A) Incurs smaller pressure drop

Description : Multimode step-index fibers have relatively large core diameters and large numerical apertures. These provide what benefit?

Last Answer : Make it easier to couple light from a light-emitting diode (LED) into the fiber.

Description : Which of the following statements is true concerning the operation of two alternators in parallel? A. The cycles per second of each alternator are the same. B. Both alternator governors must be set ... be the same on each alternator. D. The load must always be divided equally between alternators.

Last Answer : Answer: A

Description : Which of the following statements is true concerning all three-phase alternators? A. Each has three separate but identical armature windings acted on by one system of rotating magnets. B. Each has one ... The three phases always provide power to the load through three sets of slip rings and brushes.

Last Answer : Answer: A

Description : Consider the following statements with regard to a GTO : 1. The turn-off gain of the GTO is large. 2. Large negative gate current pulses are required to turn off the GTO. 3. GTO has large reverse blocking capability. Which of the ... is/are correct ? (a) 1 only (b) 2 only (c) 3 only (d) 1, 2 and 3

Last Answer : Consider the following statements with regard to a GTO : 1. The turn-off gain of the GTO is large. 2. Large negative gate current pulses are required to turn off the GTO. 3. GTO has large reverse blocking capability. Which of ... is/are correct ? (a) 1 only (b) 2 only (c) 3 only (d) 1, 2 and 3

Description : Consider the following pairs of types of bearings and applications: 1. Partial Journal bearing................... Rail wagon axles 2. Full journal bearing ......................Diesel engine crank-shaft 3. Radial bearing ... matched? [IES-2000] (a) 1 alone (b) 1 and 2 (c) 2 and 3 (d) 1, 2 and 3

Last Answer : (b) 1 and 2

Description : When two alternators are operating in parallel, the cause for circulating current is (A) increase in the excitation of one machine (B) increase in the driving torque of one machine (C) reduction in angular velocity of one machine (D) identical speed/load characteristics of both machines

Last Answer : When two alternators are operating in parallel, the cause for circulating current is (A) increase in the excitation of one machine (B) increase in the driving torque of one machine ... reduction in angular velocity of one machine (D) identical speed/load characteristics of both machines

Description : List any four salient features of 8085 microprocessor

Last Answer : Features of 8085:  1. 16 address line so 216=64 Kbytes of memory can be addressed.  2. Operating clock frequency is 3MHz and minimum clock frequency is 500 KHz.  3. On chip bus controller ... duty cycle TTL clock  10. Provide 2 serial I/O lines, so peripheral can be interfaced with 8085 μp

Description : State any four salient features of turbo- alternator.

Last Answer : Special features of a turbo alternator used in TPS: Special Futures (Highlights): It is 3-phase generator. A separate excitation is given to alternator by DC generator ( ... under voltage protection. Over frequency under frequency protection. Over load protection. Over temperature protection 

Description : List out any four salient features of hydro generator.

Last Answer : Following are the salient features of a Hydro Generator (alternator):  It is 3-ph hydro generator (alternator). It is robust in construction. A separate excitation is given to ... & under frequency protection, 5. Over temperature protection are main protections provided to generator.

Description : The entire range of the electromagnetic spectrum spans a large spectrum of wave lengths varying from: (A) 10-10 to 106 m (B) 10-8 to 106 m (C) 10-10 to 1010 m (D) 10-8 to 108 m

Last Answer : Answer: Option A

Description : The operation of a D.C. machine with large air gap lengths is comparatively (a) quiet (b) noisy (c) either of the above (d) none of the above

Last Answer : (a) quiet

Description : Which statements about alkenes and alkanes of corresponding chain lengths is true? (I) Alkenes have slightly lower melting points than alkanes (II) Alkenes have slightly higher melting points than alkanes (III) Alkenes have higher boiling ... (a) I and III (b) II and IV (c) I and IV (d) II and III

Last Answer : I and III

Description : What C is a device used to determine small lengths, of which a vernier is one type?

Last Answer : Caliper

Description : Which of the following is not the reason for greater susceptibility of smaller sensory fibres to blockade by local anaesthetics than larger motor fibres: A. Sensory fibres are inherently ... higher frequency longer lasting action potential D. Smaller fibres have shorter critical lengths for blockade

Last Answer : A. Sensory fibres are inherently more sensitive than motor fibres

Description : The axial deflection of spring for the small angle of θ is given by? a) 328PDɜN/Gd4 b) 8PDɜN/Gd4 c) 16PDɜN/Gd4 d) 8PD2N/Gdɜ

Last Answer : b) 8PDɜN/Gd4

Description : The axial deflection of spring for the small angle of θ is given by? a) 328PDᵌN/Gd⁴ b) 8PDᵌN/Gd⁴ c) 16PDᵌN/Gd⁴ d) 8PD²N/Gdᵌ

Last Answer : b) 8PDᵌN/Gd⁴

Description : Two circles intersect at A and B. AC and AD are respectively the diameters of the circles. Prove that C, B and D are collinear. -Maths 9th

Last Answer : Join CB, BD and AB, Since, AC is a diameter of the circle with centre O. ∴ ∠ABC = 90° [angle in semi circle] ---- (i) Also, AD is a diameter of the circle with center O . ∴ ∠ABD = 90° [angle in ... ⇒ ∠ABC + ∠ABD = 180° So. CBD is a straight line. Hence C, B and D are collinear . Hence proved.

Description : Two circles intersect at A and B. AC and AD are respectively the diameters of the circles. Prove that C, B and D are collinear. -Maths 9th

Last Answer : Join CB, BD and AB, Since, AC is a diameter of the circle with centre O. ∴ ∠ABC = 90° [angle in semi circle] ---- (i) Also, AD is a diameter of the circle with center O . ∴ ∠ABD = 90° [angle in ... ⇒ ∠ABC + ∠ABD = 180° So. CBD is a straight line. Hence C, B and D are collinear . Hence proved.

Description : In Fig. 10.20, two circles intersects at two points A and B.AD and AC are diameters to the circles. Prove that B lies on the line A segment DC. -Maths 9th

Last Answer : Solution :- Jion AB ∠ABD = 90° (Angle in a semicircle) Similarly, ∠ABC = 90° So, ∠ABD + ∠ABC = 90° + 90° = 180° Therefore,DBC is a line i.e.,B lies on the segment DC.

Description : If diagonals of a cyclic quadrilateral are diameters of the circle through the vertices of the quadrilateral,prove that it is a rectangle. -Maths 9th

Last Answer : Solution :- Let, ABCD be a cyclic quadrilateral such that its diagonal AC and BD are the diameters of the circle though the vertices A,B,C and D. As angle in a semi-circle is 900 ∴ ∠ABC = 900 and ∠ADC = 900 ∠DAB = 900 ... Hence, ABCD is a rectangle.

Description : AC and BD are chords of a circle that bisect each other. Prove that AC and BD are diameters and ABCD is a rectangle. -Maths 9th

Last Answer : Solution :- Let AC and BD bisect each other at point 0. Then, OA = OC and OB = OD In triangles AOB and COD, we have OA = OC OB = OD and ∠ AOB = ∠ COD (Vertically opposite angles) ∴ △ AOB ... ∠ADC Also, ∠BAD = 90° = ∠BCD Also, AB = CD and BC = DA (Proved above) Hence, ABCD is a rectangle.

Description : The outer and inner diameters of a circular pipe are 6 cm and 4 cm respectively. If its length is 10 cm, then what is the total surface -Maths 9th

Last Answer : answer:

Description : In the figure, find teh perimeter of the shaded region where. ADC, AEB and BFC are semi-circles on diameters AC, AB and BC respectively. -Maths 10th

Last Answer : Given: Diameter of semicircle AEB= 2.8 cm RADIUS OF SEMICIRCLE(AEB)= 2.8/2= 1.4 cm Diameter of semicircle BFC=1.4 cm RADIUS OF SEMICIRCLE(BFC)= 1.4/2= 0.7 cm Diameter of semicircle ADC= 2.8+1.4 = ... ; .6 = 13.2 cm Hence, the perimeter of the shaded region is 13.2 cm HOPE THIS WILL HELP YOU...

Description : Two wires of the same material but of different diameters carry the same current `i`. If the ratio of their diameters is `2:1` , then the correspondin

Last Answer : Two wires of the same material but of different diameters carry the same current `i`. If the ratio of their diameters is ... `1:1` C. `1:2` D. `1:4`

Description : The diameter of earth is 12,757 kilometers the diameter of satum is 120,664 the diameters of uranus is 51,499 is the sum of these three plantes diameters more or less than jupiter diameter of 142,804 kilometers by how much answer?

Last Answer : 2

Description : You are asked to design sewer pipes of diameters 0.4 m to 0.9 m at maximum flow, you will assume the sewer flow running at A. Full depth B. Half full C. Two third full D. Three fourth full

Last Answer : ANS: B

Description : The ratio of maximum sewage flow to average sewage flow for trunk mains having diameters more than 1.25 m, is A. 1.5 B. 2.0 C. 3.0 D. 4.0

Last Answer : ANS: A