A diode having potential difference 0.5 A across its junction which does not depend on current, is connected in series with resistance of 20 Ω across source. If 0.1 A passes through resistance, then what is the voltage of the source?

1.5 V 2.0 V 2.5 V 5 V

2.5 V

Voltage of the source, $V' = V_D + iR = 0.5+ 0.1× 20 = 2.5V$