QI: 220V, 7 Hp DC series motor coupled to a fan, the motor draws 25 A and runs at 300 rpm at terminal voltage of 220V and no external resistance, torque of the fan is proportional to the square of the speed, if Ra 0.6 2 and Rf-0.4 2. (Neglect rotational losses): a) Determine the power supplied to the fan and torque developed by the motor. b) The speed is to be reduced to 200 rpm by inserting external resistance, determine the value of this resistance and the power delivered to the fan.

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A: “Since you have asked multiple question, we will solve the first question for you. If you want any…

Q: A 230V DC series motor operates at its full load current and speed of 22A and 750 revolutions per…

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Q: A 250V series motor runs at 500 rpm at rated load current of 75 A. The armature circuit has a…

A: It is given that: V=250 VN1=500 rpmIL1=Ia1=75 ARa+Rse=0.2 Ωϕ α Ia

Q: Sketch the torque versus speed characteristic for a series-connected dc motor.

A: The circuit diagram of the DC series motor can be drawn as  Thus for constant power motor : Ns α 1Γ…

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A: When we operate the synchronous motor at overexcited mode it's power factor is leading.

Q: 2.. A three-phase 60 Hz asynchronous motor runs at 890 rpm at idle and 840 rpm at full load. ww w w…

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Q: A permanent magnet DC mitor has an armature resistance 1.4 52. When it is supplied by 75-V DC…

A:

DC Series Motors

A DC motor is a type of electric motor which converts electric energy into mechanical energy. The forces that are produced by the magnetic field are what those common types of motors rely upon. Either electro-mechanical or electronic, all types of DC motors have some internal mechanism to change the current direction in part of the DC motors. As the DC motors could be powered from existing DC lighting power distribution systems, these motors were the first form of motors widely used. By changing the strength of the current in its field winding or by using a variable supply voltage, the speed of the DC motors can be controlled over a wide range.