A diode in series with a 1.5 V supply has a voltage drop of 0.5 V. What resistance is required to obtain maximum current of the specified value?
Options

Question

A diode in series with a 1.5 V supply has a voltage drop of 0.5 V. What resistance is required to obtain maximum current of the specified value?

G1 Physics · Accepted Answer

For ideal conducting diode approximation, external resistor has V_R = 1.5 − 0.5 = 1.0 V. Given maximum current in the original question, I = 200 mA = 0.2 A, so R = V_R/I = 1/0.2 = 5 Ω. Final answer: Option C.