A synchronous motor is said to be ‘floating’ when it operates:

On high load & variable supply voltage

A synchronous condenser is virtually a/an:

Under-excited synchronous motor

Power factor of a synchronous motor can be

improved by keeping load constant and running motor over-excited

improved by keeping load constant and running motor under-excited

varied by varying the load and constant excitation

In the case of alternator cooling, a large quantity of air is passed through subslots, which are just below the main slots. Such type of cooling is known as:

Multiple inlet system of ventilation

In a relation to the synchronous machines, which of the following statement is false

The V curve of a synchronous motor represents the variation in the armature current with field excitation, at a given output power

In a salient pole machine, the direct axis synchronous reactance is greater than the quadrature axis synchronous reactance

Damper bars help the synchronous motor self-start

Short circuit ratio is the ratio of the field current required to produce the rated voltage on open circuit to the rated armature current.

The V curve of a synchronous motor represents the variation in the armature current with field excitation, at a given output power

In synchronous motor the armature current has higher values for

Both high excitation and low excitation only

Directions: It consists of two statements, one labeled as the ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answer using the codes given below:Statement (I): Dampers are used in the alternators.Statement (II): The voltage fluctuations are not reduced by the damper windings in an alternator.

Statement (I) is false but statement (II) is true

Statement (I) and Statement (II) are individually true and statement (II) is the correct explanation of statement (II)

Statement (I) and Statement (II) are individually true but statement (II) is not the correct explanation of statement (I)

Statement (I) is true but statement (II) is false

Statement (I) is false but statement (II) is true

Damper bard placed in the motor pole faces of any alternator help to reduce hunting

Above and below synchronous speed both

If a synchronous motor is running at a leading power factor, its excitation induced voltage (Ef) is

higher than the terminal voltage Vt

dependent upon supply voltage Vt

In synchronous motor, ‘V’ curves present the variation of

Armature current with maximum power developed

Armature current with excitation (field)

Armature current with maximum power developed

Field excitation with stalling torque

Field excitation with minimum power developed

A three phase star connected alternator develops an rms voltage of V1 per phase at the fundamental frequency. It also generates a third harmonic component whose rms value is V3 . What is the line voltage of the alternator?

\(\dfrac{\sqrt {V_1^2 + V_3^2}}{\sqrt 3}\)

At leading power factor, the armature flux in an alternator:

has no influence on the rotor flux

Directions: It consists of two statements, one labelled as the ‘Statement (I)’ and the other as ‘Statement (II). Examine these two statements carefully and select the answer using the codes given below:Statement (I): The ‘Rating’ of alternators is determined by their heating and hence, the losses in them.Statement (II): Along with the voltage, frequency and MVA the operating minimum lagging power factor has also to be included in the Rating specifications.

Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)

Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)

Statement (I) is true but Statement (II) is false

Statement (I) is false but Statement (II) is true

Direction: The following item consists of two statements, one labelled as ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answer using the code given below:Statement (I): Synchronous motor is a constant speed motor.Statement (II): Synchronous motor is not a self-starting motor.

Statement I is true but Statement II is false

Both Statement I and Statement II are individually true and Statement II is the correct explanation of Statement I

Both Statement I and Statement II are individually true but Statement II is not the correct explanation of Statement I

Statement I is true but Statement II is false

Statement I is false but Statement II is true

In a synchronous machine, as the machine size decreases:

p.u. armature resistance decreases and p.u. synchronous reactance increases

p.u. armature resistance increases and p.u. synchronous reactance decreases

p.u. armature resistance decreases and p.u. synchronous reactance increases

p.u. armature resistance and p.u. synchronous reactance both decreases

p.u. armature resistance and p.u. synchronous reactance both increase

In the case of an alternator connected to an infinite bus, the active power can be varied by:

changing both, prime mover speed and field excitation

In a synchronous machine, if pitch of the coil = [(r - 1) /r]th fraction of full pitch, then:

(r + 2)th harmonic can be eliminated from the induced emf in a phase

(r - 1)th harmonic can be eliminated from the induced emf in a phase

(r + 1)th harmonic can be eliminated from the induced emf in a phase

rth harmonic can be eliminated from the induced emf in a phase

Embedding the damper winding in the pole face serves which of the following purposes?

Eliminate hunting and provide adequate starting torque

Eliminate losses on account of air friction

Consider the following statements with respect to synchronous machines. State whether these statements are true or false.(a) Armature reaction is demagnetising when a generating machine supplies zero power factor lagging current.(b) Armature reaction is magnetising when a generating machine supplies zero power factor leading current.(c) Armature reaction is mostly cross-magnetising, though it has a small demagnetising component, when a generating machine supplies unity power factor current.

(a) False, (b) True and (c) True

(a) False, (b) True and (c) False

(a) True, (b) True and (c) True

(a) False, (b) True and (c) True

(a) True, (b) True and (c) False

Armature reaction in a synchronous generator at rated voltage and zero power factor leading is

magnetising and cross magnetising

demagnetising and cross magnetising

517 + Mcqs in Synchronous Motors in Electrical Engineering Page 4 McqOptions

151.	If, in a 3-ϕ alternator, a field current of 50 A produces a full-load armature current of 200 A on short-circuit and 1730 V on open circuit, then its synchronous impedance is ________ Ω
A.	3.46
B.	8.66
C.	5
D.	4
Answer» D. 4

Discussion

152.	A synchronous motor is said to be ‘floating’ when it operates:
A.	On no load and without loss
B.	On constantly varying load
C.	On pulsating load
D.	On high load & variable supply voltage
Answer» B. On constantly varying load

Discussion

153.	A synchronous condenser is virtually a/an:
A.	Over-excited synchronous motor
B.	DC motor
C.	Induction motor
D.	Under-excited synchronous motor
Answer» B. DC motor

Discussion

154.	Power factor of a synchronous motor can be
A.	improved by keeping load constant and running motor over-excited
B.	improved by keeping load constant and running motor under-excited
C.	varied by varying the load and constant excitation
D.	None of the above
Answer» D. None of the above

Discussion

155.	For unity power factor loads, the effect of an armature reaction in an alternator is
A.	magnetizing
B.	cross-magnetizing
C.	de-magnetizing
D.	distortion
Answer» C. de-magnetizing

Discussion

156.	Calculate the frequency in Hz of a 10-pole AC generator which rotates at 1800 rpm.
A.	120
B.	100
C.	150
D.	180
Answer» D. 180

Discussion

157.	In the case of alternator cooling, a large quantity of air is passed through subslots, which are just below the main slots. Such type of cooling is known as:
A.	Closed circuit ventilation
B.	Radial ventilation
C.	Multiple inlet system of ventilation
D.	Axial ventilation
Answer» E.

Discussion

158.	In a synchronous machine, the ratio of the field current required to produce rated voltage on an-open circuit to the field current required to produce rated armature current with the armature terminals shorted while the machine is mechanically run at synchronous speed is termed as:
A.	Short circuit ratio
B.	synchronous resistance
C.	synchronous impedance
D.	synchronous reactance
Answer» B. synchronous resistance

Discussion

159.	Loading capability diagram is generally drawn for
A.	Induction motor
B.	DC Generator
C.	Synchronous Generator
D.	DC Motor
Answer» D. DC Motor

Discussion

160.	At what condition synchronous motor can be used as a synchronous capacitor
A.	under-loaded
B.	under-excited
C.	Over-loaded
D.	Over-excited
Answer» E.

Discussion

161.	In order to eliminate the fifth harmonic voltage from the phase voltage of an alternator, the coil should be pitched by:
A.	72°
B.	36°
C.	15°
D.	18°
Answer» C. 15°

Discussion

162.	In a relation to the synchronous machines, which of the following statement is false
A.	In a salient pole machine, the direct axis synchronous reactance is greater than the quadrature axis synchronous reactance
B.	Damper bars help the synchronous motor self-start
C.	Short circuit ratio is the ratio of the field current required to produce the rated voltage on open circuit to the rated armature current.
D.	The V curve of a synchronous motor represents the variation in the armature current with field excitation, at a given output power
Answer» D. The V curve of a synchronous motor represents the variation in the armature current with field excitation, at a given output power

Discussion

163.	In synchronous motor the armature current has higher values for
A.	High excitation only
B.	Low excitation only
C.	Both high excitation and low excitation only
D.	None of these
Answer» D. None of these

Discussion

164.	A 500-kVA, 3.3-kV, 3-Phase star-connected alternator is found to give a short-circuit current of 110√3 A at normal field current. Estimate the magnitude of synchronous reactance if the effective winding resistance per phase is 1 ohm.
A.	Xs = √102 Ω
B.	Xs = √99 Ω
C.	Xs = √101 Ω
D.	Xs = 10 Ω
Answer» C. Xs = √101 Ω

Discussion

165.	Directions: It consists of two statements, one labeled as the ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answer using the codes given below:Statement (I): Dampers are used in the alternators.Statement (II): The voltage fluctuations are not reduced by the damper windings in an alternator.
A.	Statement (I) and Statement (II) are individually true and statement (II) is the correct explanation of statement (II)
B.	Statement (I) and Statement (II) are individually true but statement (II) is not the correct explanation of statement (I)
C.	Statement (I) is true but statement (II) is false
D.	Statement (I) is false but statement (II) is true
Answer» D. Statement (I) is false but statement (II) is true

Discussion

166.	Damper bard placed in the motor pole faces of any alternator help to reduce hunting
A.	Above synchronous speed only
B.	Below synchronous speed only
C.	Above and below synchronous speed both
D.	None of the above
Answer» D. None of the above

Discussion

167.	If a synchronous motor is running at a leading power factor, its excitation induced voltage (Ef) is
A.	equal to terminal voltage Vt
B.	higher than the terminal voltage Vt
C.	less than terminal voltage Vt
D.	dependent upon supply voltage Vt
Answer» C. less than terminal voltage Vt

Discussion

168.	A 3-phase, 12-pole alternator driven at a speed of 500 rpm supplies power to an 8-pole, 3-phase inductor motor. Calculate the approximate full load speed of the motor if the slip of the motor at full load is 3%.
A.	615 rpm
B.	730 rpm
C.	510 rpm
D.	800 rpm
Answer» C. 510 rpm

Discussion

169.	In case of alternators with single-layer concentric windings, the number of slots is equal to _________ the number of coils.
A.	thrice
B.	quad
C.	half
D.	twice
Answer» E.

Discussion

170.	Hunting occurs in a/an __________ motor.
A.	DC shunt
B.	synchronous
C.	DC series
D.	induction
Answer» C. DC series

Discussion

171.	In a salient pole synchronous motor, the developed reluctance torque attains the maximum value when the load angle in electrical degrees is
A.	0
B.	45
C.	60
D.	90
Answer» C. 60

Discussion

172.	A 20-pole alternator is having 180 identical stator slots with 6 conductors in each slot. All the coils of a phase are in series. If the coils are connected to realize single-phase winding, the generator voltage is V1. If the coils are reconnected to realize three-phase star-connected winding, the generated phase voltage is V2. Assuming full pitch, single-layer winding, the ratio V1/V2 is
A.	\(\frac{1}{{\sqrt 3 }}\)
B.	\(\frac{1}{2}\)
C.	\(\sqrt 3 \)
D.	2
Answer» E.

Discussion

173.	In synchronous motor, ‘V’ curves present the variation of
A.	Armature current with excitation (field)
B.	Armature current with maximum power developed
C.	Field excitation with stalling torque
D.	Field excitation with minimum power developed
Answer» B. Armature current with maximum power developed

Discussion

174.	In the synchronous motor, the rotor copper losses are met by
A.	Motor input
B.	Armature input
C.	Supply lines
D.	D.C. source
Answer» E.

Discussion

175.	A synchronous machine is connected to an infinite bus. The armature current change with field current for constant real power is
A.	a V curve
B.	an inverted V curve
C.	constant curve
D.	dependent on the power factor
Answer» B. an inverted V curve

Discussion

176.	A three phase star connected alternator develops an rms voltage of V1 per phase at the fundamental frequency. It also generates a third harmonic component whose rms value is V3 . What is the line voltage of the alternator?
A.	\(\sqrt {3(V_1^2 + V_3^2)}\)
B.	\(\sqrt {(V_1^2 + V_3^2)}\)
C.	\(\dfrac{\sqrt {V_1^2 + V_3^2}}{\sqrt 3}\)
D.	\(\sqrt {2(V_1^2 + V_3^2)}\)
Answer» B. \(\sqrt {(V_1^2 + V_3^2)}\)

Discussion

177.	An alternator has 18 slots per pole and the first coil lies in slots 1 and 16. Calculate the pitch factor of the coil for 3rd harmonic.
A.	1.5
B.	2.5
C.	0.707
D.	3
Answer» D. 3

Discussion

178.	For lagging load power factor, the field of synchronous motor is:
A.	overexcited
B.	underexcited
C.	normally excited
D.	not excited
Answer» C. normally excited

Discussion

179.	Consider the following statements:1. A synchronous motor has no starting torque but when started it always runs at a fixed speed.2. A single-phase reluctance motor is not self-starting even if path for eddy currents are provided in the rotor3. A single-phase hysteresis motor is self-startingWhich of these statement(s) is/are correct?
A.	1, 2 and 3
B.	1 only
C.	1 and 2 only
D.	2 and 3 only
Answer» B. 1 only

Discussion

180.	At leading power factor, the armature flux in an alternator:
A.	opposes the rotor flux
B.	aids the rotor flux
C.	has no influence on the rotor flux
D.	distorts the rotor flux
Answer» C. has no influence on the rotor flux

Discussion

181.	Directions: It consists of two statements, one labelled as the ‘Statement (I)’ and the other as ‘Statement (II). Examine these two statements carefully and select the answer using the codes given below:Statement (I): The ‘Rating’ of alternators is determined by their heating and hence, the losses in them.Statement (II): Along with the voltage, frequency and MVA the operating minimum lagging power factor has also to be included in the Rating specifications.
A.	Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
B.	Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)
C.	Statement (I) is true but Statement (II) is false
D.	Statement (I) is false but Statement (II) is true
Answer» B. Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)

Discussion

182.	A synchronous motor is operating at constant load, while its excitation is adjusted to get unity power factor. If the excitation is now increased, the power factor will be?
A.	Leading
B.	Remains at unity
C.	Lagging
D.	Becomes zero
Answer» B. Remains at unity

Discussion

183.	Direction: The following item consists of two statements, one labelled as ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answer using the code given below:Statement (I): Synchronous motor is a constant speed motor.Statement (II): Synchronous motor is not a self-starting motor.
A.	Both Statement I and Statement II are individually true and Statement II is the correct explanation of Statement I
B.	Both Statement I and Statement II are individually true but Statement II is not the correct explanation of Statement I
C.	Statement I is true but Statement II is false
D.	Statement I is false but Statement II is true
Answer» C. Statement I is true but Statement II is false

Discussion

184.	In a synchronous machine, as the machine size decreases:
A.	p.u. armature resistance increases and p.u. synchronous reactance decreases
B.	p.u. armature resistance decreases and p.u. synchronous reactance increases
C.	p.u. armature resistance and p.u. synchronous reactance both decreases
D.	p.u. armature resistance and p.u. synchronous reactance both increase
Answer» B. p.u. armature resistance decreases and p.u. synchronous reactance increases

Discussion

185.	A 10 KVA, 200 V single-phase alternator with a 5 A disturbance produces a voltage of 200 V in the absence of load. When the terminals of the armature are short-circuited, the rated armature current flows with a disturbance of 2A. What would be its per unit impedance with a base voltage of 200 V and a base kVA of 20?
A.	1.6
B.	0.4
C.	0.8
D.	0.2
Answer» D. 0.2

Discussion

186.	Calculate the frequency of the rotor current when the synchronous speed is 1,500 rpm and rotor speed is 1,440 rpm and supply frequency is 50 Hz.
A.	2 Hz
B.	5 Hz
C.	1 Hz
D.	0.5 Hz
Answer» B. 5 Hz

Discussion

187.	In the case of an alternator connected to an infinite bus, the active power can be varied by:
A.	changing both, prime mover speed and field excitation
B.	changing the prime mover speed
C.	changing the field excitation
D.	changing the power factor
Answer» C. changing the field excitation

Discussion

188.	An over-excited synchronous motor at no load acts as:
A.	capacitor
B.	inductor
C.	transformer
D.	resistor
Answer» B. inductor

Discussion

189.	In a synchronous machine, if pitch of the coil = [(r - 1) /r]th fraction of full pitch, then:
A.	(r + 2)th harmonic can be eliminated from the induced emf in a phase
B.	(r - 1)th harmonic can be eliminated from the induced emf in a phase
C.	(r + 1)th harmonic can be eliminated from the induced emf in a phase
D.	rth harmonic can be eliminated from the induced emf in a phase
Answer» E.

Discussion

190.	Embedding the damper winding in the pole face serves which of the following purposes?
A.	Eliminate hunting and provide adequate starting torque
B.	Reduce windage losses
C.	Eliminate losses on account of air friction
D.	Reduce bearing friction
Answer» B. Reduce windage losses

Discussion

191.	As load power factor of an alternator becomes more leading, the value of generated voltage required to give rated terminal voltage:
A.	remains unchanged
B.	increases
C.	varies with rotor speed
D.	decreases
Answer» E.

Discussion

192.	Consider the following statements with respect to synchronous machines. State whether these statements are true or false.(a) Armature reaction is demagnetising when a generating machine supplies zero power factor lagging current.(b) Armature reaction is magnetising when a generating machine supplies zero power factor leading current.(c) Armature reaction is mostly cross-magnetising, though it has a small demagnetising component, when a generating machine supplies unity power factor current.
A.	(a) False, (b) True and (c) False
B.	(a) True, (b) True and (c) True
C.	(a) False, (b) True and (c) True
D.	(a) True, (b) True and (c) False
Answer» C. (a) False, (b) True and (c) True

Discussion

193.	A 500 kVA, 2300 V, 3-phase star connected alternator has a full load armature resistance drop of 50 V per phase and an effective reactance drop of 500 V per phase. The percentage regulation at UPF is
A.	1.05
B.	10.5
C.	21.8
D.	28.7
Answer» C. 21.8

Discussion

194.	If the no-load voltage of a 3-phase, 440 V, 50 Hz alternator is 495 V, then its voltage regulation is:
A.	12.5%
B.	10.5%
C.	34%
D.	10%
Answer» B. 10.5%

Discussion

195.	A separately excited DC generator supplies 150 A to 145 V DC grid. The generator is running at 800 RPM. The armature resistance is 0.1 Ω. If the speed of the generator is increased to 1000 RPM, the current supplied by the generator to the DC grid is
A.	550 A
B.	600 A
C.	700 A
D.	800 A
Answer» B. 600 A

Discussion

196.	Armature reaction in a synchronous generator at rated voltage and zero power factor leading is
A.	magnetizing
B.	demagnetising
C.	magnetising and cross magnetising
D.	demagnetising and cross magnetising
Answer» B. demagnetising

Discussion

197.	A 150 kW, 1200 rpm, 250 V, three phase delta connected synchronous motor has synchronous reactance of 1 Ω per phase. if the excitation voltage is fixed at 400 V per phase, power output at a torque angle of 30 degrees is:
A.	75 kW
B.	25 kW
C.	87 kW
D.	50 kW
Answer» E.

Discussion

198.	A star winding supplied from a three phase 60 Hz system is required to produce a magnetic flux rotating at 900 rev/min. Determine no. of poles
A.	8
B.	16
C.	4
D.	2
Answer» B. 16

Discussion

199.	In case of two-layer winding in stator of alternators, each slot in stator contains _________.
A.	two coil sides
B.	four coil sides
C.	three coil sides
D.	one coil side
Answer» B. four coil sides

Discussion

200.	A two-pole alternator is running at 1,500 rpm. Its angular velocity will be _______.
A.	192 rad / s
B.	157 rad / s
C.	212 rad / s
D.	118 rad / s
Answer» C. 212 rad / s

Discussion

Explore topic-wise MCQs in Electrical Engineering.

If, in a 3-ϕ alternator, a field current of 50 A produces a full-load armature current of 200 A on short-circuit and 1730 V on open circuit, then its synchronous impedance is ________ Ω

A synchronous motor is said to be ‘floating’ when it operates:

A synchronous condenser is virtually a/an:

Power factor of a synchronous motor can be

For unity power factor loads, the effect of an armature reaction in an alternator is

Calculate the frequency in Hz of a 10-pole AC generator which rotates at 1800 rpm.

In the case of alternator cooling, a large quantity of air is passed through subslots, which are just below the main slots. Such type of cooling is known as:

In a synchronous machine, the ratio of the field current required to produce rated voltage on an-open circuit to the field current required to produce rated armature current with the armature terminals shorted while the machine is mechanically run at synchronous speed is termed as:

Loading capability diagram is generally drawn for

At what condition synchronous motor can be used as a synchronous capacitor

In order to eliminate the fifth harmonic voltage from the phase voltage of an alternator, the coil should be pitched by:

In a relation to the synchronous machines, which of the following statement is false

In synchronous motor the armature current has higher values for

A 500-kVA, 3.3-kV, 3-Phase star-connected alternator is found to give a short-circuit current of 110√3 A at normal field current. Estimate the magnitude of synchronous reactance if the effective winding resistance per phase is 1 ohm.

Damper bard placed in the motor pole faces of any alternator help to reduce hunting

If a synchronous motor is running at a leading power factor, its excitation induced voltage (Ef) is

A 3-phase, 12-pole alternator driven at a speed of 500 rpm supplies power to an 8-pole, 3-phase inductor motor. Calculate the approximate full load speed of the motor if the slip of the motor at full load is 3%.

In case of alternators with single-layer concentric windings, the number of slots is equal to _________ the number of coils.

Hunting occurs in a/an __________ motor.

In a salient pole synchronous motor, the developed reluctance torque attains the maximum value when the load angle in electrical degrees is

In synchronous motor, ‘V’ curves present the variation of

In the synchronous motor, the rotor copper losses are met by

A synchronous machine is connected to an infinite bus. The armature current change with field current for constant real power is

A three phase star connected alternator develops an rms voltage of V1 per phase at the fundamental frequency. It also generates a third harmonic component whose rms value is V3 . What is the line voltage of the alternator?

An alternator has 18 slots per pole and the first coil lies in slots 1 and 16. Calculate the pitch factor of the coil for 3rd harmonic.

For lagging load power factor, the field of synchronous motor is:

At leading power factor, the armature flux in an alternator:

A synchronous motor is operating at constant load, while its excitation is adjusted to get unity power factor. If the excitation is now increased, the power factor will be?

In a synchronous machine, as the machine size decreases:

Calculate the frequency of the rotor current when the synchronous speed is 1,500 rpm and rotor speed is 1,440 rpm and supply frequency is 50 Hz.

In the case of an alternator connected to an infinite bus, the active power can be varied by:

An over-excited synchronous motor at no load acts as:

In a synchronous machine, if pitch of the coil = [(r - 1) /r]th fraction of full pitch, then:

Embedding the damper winding in the pole face serves which of the following purposes?

As load power factor of an alternator becomes more leading, the value of generated voltage required to give rated terminal voltage:

A 500 kVA, 2300 V, 3-phase star connected alternator has a full load armature resistance drop of 50 V per phase and an effective reactance drop of 500 V per phase. The percentage regulation at UPF is

If the no-load voltage of a 3-phase, 440 V, 50 Hz alternator is 495 V, then its voltage regulation is:

A separately excited DC generator supplies 150 A to 145 V DC grid. The generator is running at 800 RPM. The armature resistance is 0.1 Ω. If the speed of the generator is increased to 1000 RPM, the current supplied by the generator to the DC grid is

Armature reaction in a synchronous generator at rated voltage and zero power factor leading is

A 150 kW, 1200 rpm, 250 V, three phase delta connected synchronous motor has synchronous reactance of 1 Ω per phase. if the excitation voltage is fixed at 400 V per phase, power output at a torque angle of 30 degrees is:

A star winding supplied from a three phase 60 Hz system is required to produce a magnetic flux rotating at 900 rev/min. Determine no. of poles

In case of two-layer winding in stator of alternators, each slot in stator contains _________.

A two-pole alternator is running at 1,500 rpm. Its angular velocity will be _______.