Hm, If an electrical circuit has no resistance or negligible R then shock circuit is likely to occur.....what's the matter in case of electric motor please explain
electric motors provide resistance primarily in the winding coils on the stator... common DC motors produce resistance from winding and brushes... a simple concept is, the more winding there is on the stators, the slower the motor will spin for an equal given voltage, and the less amps it will use (as the winding wires will be thinner and produce more resistance)... most electric DC motors are wound over 40 times, as found in common toy motors... however some hobby outrunner 3phase/AC motors may be wound only 6,8, or 10 times, giving VERY low resistance, spinning at high RPMs (45-60 thousand), and because of the thick wires, takes more than 50 to 100 AMPS of power...
Hi, The electrical circuit that possesses resistance are the windings of a motor.A motor has two types of windings viz. Field windings and Armature windings. See,when we talk of only resistance then it is logical to understand the theory of a dc motor only(NOT ac motor) in regards to your question. In general,the resistance of field windings is maintained HIGH by using a coil of larger number of turns made by thin copper wires as the resistance is inversely proportional to the area of cross section of the wire. This is because,the initial applied voltage to the field windings is very high and may cause to generate a large current in field circuit in case of low resistive windings.(Remember Ohm's law). This initial transient current is very damaging and so undesirable for use in the field circuit. On the other hand,the resistance of armature windings is kept LOW by using small number of turns made of copper wires of larger area of cross section. This is because the armature circuit is rotary member of the motor and has capability of self limiting the resistance in the form of BACK EMF. Even the initial value of current is very much high in armature circuit too but the use of STARTERS limit the current by grading the value of effective resistance.Once the rotor attains sufficient rpm,the generation of BACK EMF now,limits the current in the circuit and starters are removed. So,this is a misconception that motor circuits do not have resistances. HOPE IT WORKED!!!
