Why is the starting current high in a DC motor?

Answer Posted / bharat

In DC motors, Voltage equation is V=Eb-IaRa
V = Terminal voltage
Eb = Back emf in Motor
Ia = Armature current
Ra = Aramture resistance

At starting, Eb is zero. Therefore, V=IaRa
Ia = V/Ra where Ra is very less like 0.01ohm.
i.e, Ia will become enoromously increased.

Ref. Electrical Technology Auth : BL Theraja, Vol-I & II.

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