What is the voltage in the section of the circuit, on which, at a current of 2 A, 800 J was performed in 20 s?

Initial data: I (current in the circuit section) = 2 A; t (time of work) = 20 s; A (the amount of work that was done on the section of the chain) = 800 J.

The desired voltage in the selected section of the circuit is determined from the formula: A = U * I * t, whence U = A / (I * t).

Let’s make the calculations: U = 800 / (2 * 20) = 20 V.

Answer: In the section of the circuit, the effective voltage is 20 V.