Help with physic please ?

Question

When AC is changed into DC to charge a laptop or phone, is the resulting voltage perfectly constant?

A. Yes

B. No, but it can be made pretty close

C. No, in fact sometimes it's negative

Answer 1

Actually, the wave nature of alternating current remains even in the DC output. Basically, you use something called as rectifier for converting AC to DC. The output DC is not a constant but a rippling pulse which is in the constant direction. Hope this helps.