How much resistance must a 9-V device have to keep the current at about 1A?

To determine the resistance needed to keep the current at about 1A for a 9-V device, you can use Ohm's Law, which states that ( V = I \times R ). Rearranging the formula to find resistance gives ( R = \frac{V}{I} ). Substituting the values, ( R = \frac{9V}{1A} = 9 , \Omega ). Therefore, the device must have a resistance of approximately 9 ohms.