What amount of heat is released in the filament of the lamp for 20 seconds if at a voltage of 10 volts the current is 0.2 A.

To find out the amount of heat released in the filament of the presented lamp, we use the formula: Q = U * I * t, where U is the voltage across the filament (U = 10 V); I – operating current (I = 0.2 A); t – considered time (t = 20 s).

Let’s perform the calculation: Q = U * I * t = 10 * 0.2 * 20 = 40 J.

Answer: In 20 seconds, 40 J of heat should have been released on the filament of the presented lamp.