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An electric motor operating on 50 V.D.C ...

An electric motor operating on 50 V.D.C supply draws a current of 12 ampere. If the efficiency of motor is 30%, estimate the resistance of the motor.

Text Solution

Verified by Experts

`eta= 30%= (3)/(100), E= 50V`
`eta= ("Back emf")/("Applied emf")= (e )/(E )`
`(30)/(100)= (e )/(50)`
`e= 15V`
`I= 12A" "` (Given)
We know, `I= (E-e)/(R )`
`R= (E-e)/(I)`
`R= (50-15)/(12)`
`R= (35)/(12)= 2.9 Omega`.
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