Which rule is used to determine the direction of the magnetic field around a straight current-carrying conductor?

Kirchhoff's Current Law (KCL), which dictates that the sum of all currents entering a junction equals the sum of currents leaving, is fundamentally based on the physics principle of:

A current of 4 Amperes flows through a resistor with a resistance of 8 Ohms. According to Ohm's Law, what is the voltage drop across the resistor?

Electrical circuit problem 19: If a direct current of 2 Amperes flows through a resistor when a potential difference of 39 Volts is applied, what is its resistance?

Electrical circuit problem 18: If a direct current of 2 Amperes flows through a resistor when a potential difference of 38 Volts is applied, what is its resistance?

Electrical circuit problem 17: If a direct current of 2 Amperes flows through a resistor when a potential difference of 37 Volts is applied, what is its resistance?

Electrical circuit problem 16: If a direct current of 2 Amperes flows through a resistor when a potential difference of 36 Volts is applied, what is its resistance?