Question

A dc motor operates with 220v mains initially it draws a current of 20a

Answer 1

Answer ⇒ The power of the appliance is 4.4 kW.

Explanation ⇒ Hey Question is incomplete.

On my Knowledge, I think the correct Question will be,

Question. ⇒ A dc motor operates with 220v mains initially it draws a current of 20A. Find the Power of the Appliance?

Solution ⇒

Given conditions,

   Potential (V) = 220 V,

     Current(I) = 20 A.

Using the formula,

   Power = Potential × Current.

∴ Power = 220 × 20

∴ Power = 4400 W.

OR Power = 4.4 kW.

Hence, the power of the appliance is 4.4 kW.

Hope it helps.

Answer 2

The equation for the motor is given as:

V = E + IR

Solving for E

E = V- IR  

E = 220 – (20)(6)                           (Armature Resistance is ignored)  

E = 100 V

Now we know that:

P = IE

I = P/E

I = 500/100

I = 5 A