A typical V/I characteristic for a forward-biased P-N junction. It is seen that forward current rises exponentially with the applied forward voltage. However, at ordinary room temperature, a p.d. of about 0.3 V is required before a reasonable amount of forward current starts flowing in a germanium junction. This voltage is known as threshold voltage (Vth) or cut-in voltage or knee voltage VK. It is practically the same as barrier voltage VB. Its value for silicon junction is about 0.7 volt. For V < Vth, current flow is negligible. But as applied voltage increases beyond the threshold value, the forward current increases sharply. If forward voltage is increased beyond a certain safe value, it will produce an extremely large current which may destroy the junction due to overheating.
Aircraft Maintenance Engineering AME of an aircraft have to complete EASA part 66 modules in EASA 147 approved training organizations for justifying theoretical and practical training with qualification. Aircraft maintenance engineer responsibilities for maintenance of an aircraft.