A diode with 100 Ω external resistance and a battery of emf 3.5 V has a forward diode drop of 0.5 V. Find the current.
Options

Question

A diode with 100 Ω external resistance and a battery of emf 3.5 V has a forward diode drop of 0.5 V. Find the current.

G1 Physics · Accepted Answer

External resistor voltage V_R = V_battery − V_diode = 3.5 − 0.5 = 3.0 V. Ohm’s law gives I = V_R/R = 3/100 = 0.03 A = 30 mA. Final answer: Option A.