FCC Technician Exam Question Of The Day (T5D06)

Q) What is the resistance of a circuit that draws 4 amperes from a 12-volt source?

A) 3 ohms

NJ2X Notes:
Ohm's Law was discovered by Georg Simon Ohm and is worth committing to memory:

E = I * R

or by manipulating the terms algebraically:

I = E / R

or

R = E / I

In this example:
R = E / I
R = 12 volts / 4 amperes = 3 ohms