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I read question from someone who was having monitor with 90 W power, 19 V and 3.32 A rating. When calculated using volt and power the amp came out to be 4.74 A. I didn't understand why is there requirement to find amp rating. If we consider 3.32 A as a minimum then we can take any ampere rating higher than 3.32 A.
Is there any need of any calculation? By reading the posts what I understood is that there is no harm in having a higher amp rating as power supply will draw only the required and discard the rest.