A resistor of 5 is in parallel with a resistor of 8 . What is the approximate equivalent resistance?
A.
B.
C.
D.
A
Equivalent resistance is found by calculating
which is approximately 3W. A quick way of solving this problem is to remember that equivalent resistances for resistors in parallel are always less than either of the individual resistors. Since answer A is the only choice less than both individual resistors, A can be chosen as the answer without any calculation.