(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A dc series motor takes a full load current of 10 A from a 12 V voltage source .The iron,friction and windage losses account to 9% of the input power .the field winding resistance is 0.1 ohms and the armature resistance is 0.15 ohms and the voltage drop is 2 V .Calculate the power output and the overall efficiency ?

2. Relevant equations

3. The attempt at a solution

Okay so first the I armature =I load=I field =10Amp hence power in= Ia?*Vt =10*12=120 W

The I calculated all the losses p losses (windage) = 0.09*120 = 10.8 Watts ,p losses in the core = Ia^2*r =100*(0.25)=25 Watts

Also the brush losses =Vb*Ia= 2*10 =20 Watts ,therefore p output= 120-10.8-25-20 =64.2 watts and the efficiency is p output/p input =64.2/120 =53.5% .

Okay I just need someone to check if I have done the right thing here please ? Thank u

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# Homework Help: Series motors question?

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