Posted by Sola on .
When a certain a.c. supply is connected to a lamp, it lights with the same brightness as it does with a 12V battery
a) what is the r.m.s. value of the a.c. supply?
b) what is the peak p.d. of the a.c. supply?
Isn't rms value the same effective value as DC? What does root mean square give you if not that?