1 / R + 1 / 400 = 5 / R
1 / 400 = 4 / R
A resistor R is connected to a 12 V battery. The total current increases five times when a 400 Ohm resistor is added in parallel with it. The value of resistance R is?
Please help me.
2 answers
if the current increased 5 times, that means the new resistor of 400 ohms is carrying 4 times the current as the original resistor, which means the original resistor has to be 4x as much, or 1600 ohms. Scott is right.