What is lost voltage? Md. Saifur Rahman For an electromotive source, due to its own internal resistance, some of the voltage is reduced. This is known as lost voltage.You may likeDo I need car insurance?What is car insurance?How could I get cheaper car insurance?What is auto insurance?Why Adulterant food is the barrier to sound health?What are the producers?What are food preservatives?What is food chain?What is tertiary consumer?