The potential difference across a variable resistor is 11v and the current flowing through it is 0.4a.

what is the present resistance of this variable resistor?

Considering the Ohm's law, the resistance of the resistor is 27.5 Ω.

You must first know the following definitions:

The relationship between current, voltage and resistance is expressed by Ohm's law, which determines that the current flowing in a circuit is directly proportionate to the applied voltage and inversely proportional to the resistance of the circuit, as long as the temperature remains constant.

Mathematically, Ohm's law is expressed by the expression:

where I is the intensity that is measured in amps (A), V the voltage that is measured in volts (V); and R is the resistance that is measured in ohms (Ω).

In this case, you know:

Replacing in Ohm's law:

Solving:

R×0.4 A= 11 V

R= 27.5 Ω

Finally, the resistance of the resistor is 27.5 Ω.

Learn more:

Resistance = (potential difference) / (current)

Resistance = (11 V) / (0.4 A)

Resistance = 27.5 ohms

c. magnitude and direction