A 50-hp, 550-V shunt motor has an armatureresistance, including brushes, of 0.36Ω . Whenoperating at rated load and speed, the armature takes75 A. What resistance should be inserted in thearmature circuit to obtain a 20 percent speedreduction when the motor is developing 70 percent ofrated torque? Assume that there is no flux change.

Q: Give the relevant details for drawing lap winding for a de machine with 4 poles, 22 slots and 6…

A: We need to give relevant details for drawing a lap winding for a dc machine having, Poles (P) = 4…

Q: 1. Laminations of core are generally made of. e.+ Si 37. 2. In case of the induction motors the…

A:

Q: The induced torque in dc motors beyond the pole edges is Select one: O a. infinity Ob. 180 V OC. 220…

A: The diagram of the dc motor loop segment connected to the external source is shown below:  The…

Q: An induction motor develops rated torque with a slip of 3.5% when the rotor is cold. If the rotor…

A: Answer : given that an induction motor develops rated torque with  a slip of S = 3.5%= 0.035 rotor…

Q: A compound DC motor with lap-wound armature is connected to a 132V source. Shunt field resistance is…

A: As per the guidelines given, We can only provide the solution of the first three questions in…

Q: A 230 V dc series motor has an armature resistance of 0.2 ohm and field resistance of 0.1 ohm at…

A: Given, Supply voltage, V= 230 V Armature resistance, Ra= 0.2 ohm Field resistance, Rse= 0.1 ohm Line…

Q: What are the various losses in an Induction motor? On what factors do they depend?

A: the fallowing are the various losses that occur in induction motor:

Q: A three-phase, four-pole, 208 V, 60 Hz, Y-connected, induction motor has the following parameters,…

A: Given data : 208 v , 60 hz R1 =0.22 X1=0.43Xm = 15 Rc=∞P = 4 R2=0.127X2=0.43Solution (a)rms value of…

Q: Calculate the flux per pole required on full-load for a 50 kW, 450 V, 8-pole, 600 r.p.m. d.c. shunt…

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Q: An 8 pole, 50 Hz slip ring induction motor runs at a slip of 2.67% on full load. The rotor…

A: Initial slip is given  s=2.67%=0.0267 Resistance is given R2=0.2 ohm When torque is constant slip is…

Q: A 120 V shunt motor has an armature equivalent of 0.5 ohm and a field resistance of 60 ohm. At full…

A: Given data, Armature resistance Ra=0.5 Ω Field resistance Rf=60 Ω Terminal voltage V = 120 V Load…

Q: the relation between armature and field currents in a series connected DC motor is O It = If + la O…

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Q: An induction motor having full load torque of 60 Nm when delta-connected develops a starting torque…

A: An induction motor- Delta-connection- Full load torque=60 N-m, Starting torque = 120 N-m, To Find-…

Q: armature winding of a 200-V, 4-pole, series motor is lap-connected. There are 280 slots and each…

A: We need to find out speed for given motor

Q: A 415V squirrel cage induction motor develops a torque of 40Nm. The torque developed by the motor if…

A:

Q: A 10 kW, 250 V shunt motor has an armature resistance of 0.5 Ω and a field resistance of 200 Ω. At…

A: Back emf  of motor=terminal voltage- voltage drop in armature resistance . Back emf of dc motor is…

Q: A 900 rpm, 4 pole wave wound shunt motor takes 300 A. The flux per pole is 0.02 Wb and the armature…

A: A 900 rpm, 4 pole wave wound shunt motor takes 300 A. The flux per pole is 0.02 Wb and the armature…

Q: A dc shunt generator delivers 50 kw at 250 v, its armature has a 4-pole wave winding with a…

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Q: 3. A 4 pole, 250 dc shunt motor has a lap connected armature with 960 conductors. The flux per pole…

A: In this question,  Torque develop by the armature in N-m.  Torque T= power/(2πN/60) N-m If the…

Q: On full-load a 300 V series motor takes 90A and runs at 15 rev/s. The armature resistance is 0.1 ohm…

A: Given- For series motor- Voltage at terminal = 300 V Current = 90 A Speed = 15 rev/sec Armature…

Q: pole. 50-Hz. 3-ϕ induction motor has a full-load speed of 950 rpm. At half load its speed would be…

A: Given: no. of poles, P = 6 (assuming since the given has missing data)frequency, f = 50 Hzrotor…

Synchronous Motor

The synchronous motor is an AC electric type motor where at a steady-state the shaft rotation is synchronized with the supply current variable-frequency. To an integral number of AC cycles, the rotation period is exactly equal. The stator of the motor in the synchronous motor contains multi-phase AC electromagnets due to which a magnetic field is created that rotates in time with the oscillation of the line current. The rotor contains a permanent magnet and the rotor rotates in synchronization with the stator field at the same rate and provides the second synchronized magnetic field which is rotating in nature as a result. When the synchronous motor is supplied with independently excited multi-phase AC electromagnets on both the rotor and the stator, it is termed as a doubly-fed machine. The most widely used AC-type motors are the synchronous AC motor and the induction AC motors.