Draw a graph of the change in current in the circuit if its resistance is 20 ohms, and the voltage changes from 30 to 60 V.

According to Ohm’s law, current is directly proportional to voltage, and inversely proportional to resistance.

I = U / R, then the graph of the change in the current in the circuit will be a straight line.

Determine the current in the circuit at the minimum and maximum voltage values.

I1 = U1 / R = 30/20 = 1.5 A.

I2 = U2 / R = 60/20 = 3 A.

Since the resistance is constant, we will postpone the voltage of the network along the abscissa, and the current strength along the ordinate.