Stu wanted to calculate the resistance of a light bulb connected to a 4.0-V battery, with a resulting current of 0.5 A. He used the formula R = VI and obtained an answer of 2 . Was Stu’s answer correct? How do you know?
Stu's answer is incorrect. We can determine this by using the formula for resistance, which states that R = V/I, where V is voltage and I is the current.
For Stu's calculation, we have a voltage (V) of 4.0 volts and a current (I) of 0.5 amps. Plugging these values into the formula, we get R = 4.0 V / 0.5 A = 8 Ohms.
The correct resistance of the light bulb is therefore 8 Ohms, not 2 Ohms as Stu calculated.
No, Stu's answer is not correct. We can tell because the formula for resistance is usually written as R = V/I, where V is the voltage and I is the current.
Using this formula, we can calculate the resistance using Stu's values:
R = V / I = 4.0 V / 0.5 A = 8 ohms
So the correct resistance is 8 ohms, not 2 ohms.