Well *externally* distinguishing a Medha & Bombardier is out of my knowledge. Anyways we have an "assumption". To understand,read as follows
๐ธKolkata EMUs operate in Howrah div,Sealdah div & Kharagpur div only. All these divisions have received 3PH EMU Rake. HWH & KGP div only operate Medha 3PH EMUs while SDAH div has complete Bombardier stock.
๐Lets come to externally distinguishing feature ASSUMED by us
.......
more... According to observations,
๐ธBombardier EMUs make no rythimic sound during accleration/deceleration (Video No.1,listen from 01:30 to 01:50)
๐ธMedha EMUs make a rythimic sound (Video No.2 , carefully listen from 01:18 to 01:23)
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๐Again,this is just an assumption ... Others may highlight if knwon.