Calculate the resistance of an electric hotplate if it consumes 800 wells of energy in 20 minutes at a current of 4 amperes.

Given:

I = 4 Amperes – the strength of the current passing through the electric plate;

Q = 800 kJ = 800000 Joules – the energy consumed by the electric stove;

t = 20 minutes = 1200 seconds – the period of time during which the tile consumes energy Q.

It is required to determine R (Ohm) – the resistance of the hotplate.

Let’s find the power of the electric stove:

W = Q / t = 800000/1200 = 666.7 watts.

Then the voltage is:

U = W / I = 666.7 / 4 = 166.7 Volts.

The tile resistance will be equal to:

R = U / I = 166.7 / 4 = 41.7 Ohm.

All calculations have been rounded to one decimal place.

Answer: the resistance is 41.7 ohms.