a 25v heater has two elements, one of which is missing. if the resistance of the remaining element is measured to be 50 ohm,what must the resistance of a second element be when connected in parallel to maintain a current of 1 amp.

Answer 1

i = 25/Requivalent = 1 amp
so we need
Req = 25

In parallel
Req = R1R2/(R1+R2)
25 = 50 R2/(50+R2)

25 (50 + R2) = 50 R2
50 + R2 = 2 R2
R2 = 50

which we could have guessed :)