The electric stove has two heating coils, each of which in working condition has a resistance R = 100

The electric stove has two heating coils, each of which in working condition has a resistance R = 100 ohms at a voltage of U = 220 V by how much the current power when the P2 spirals are connected in parallel differs from the current power P1 when they are connected in series.

Let’s write Ohm’s law for a circuit consisting of two identical loads R when connected in series:

I = U / (R + R);

I = U / 2R.

Then the power is equal to:

P1 = U ^ 2 / 2R.

Parallel connection:

I = U / (1 / R + 1 / R);

I = U * R / 2.

P2 = U ^ 2 * 2 / R.

Then the power difference will be:

P2 – P1 = U ^ 2 * 2 / R – U ^ 2 / 2R = U ^ 2 * (2 / R – 1 / 2R) = 4U ^ 2 / 3R.

We substitute the given values into the resulting formula:

P2 – P1 = 4 * 220 ^ 2/3 * 100 = 645 W.

Answer: when connected in parallel, the power increases by 645 watts.