Question

which wire, when current flows through it, would be surrounded by the strongest magnetic field?

Explanation:

Step1: Recall Magnetic Field from Current

A current - carrying wire produces a magnetic field. The strength of the magnetic field around a current - carrying wire depends on the current and the shape of the wire. For a solenoid - like (coiled) wire, the magnetic fields from each turn of the coil add up. A straight wire has a magnetic field that is given by the formula $B=\frac{\mu_0I}{2\pi r}$ (for a long straight wire), while a coiled wire (like a solenoid or a coil) has a magnetic field inside it that is $B = \mu_0nI$ (where $n$ is the number of turns per unit length and $I$ is the current). When we compare a straight wire and a coiled wire carrying the same current, the coiled wire will have a stronger magnetic field around it (especially inside the coil, but also in the vicinity) because the magnetic fields from each loop of the coil reinforce each other.

Step2: Analyze the Given Wires

In the problem, we have a straight wire and a coiled (loop - like) wire. When current flows through the coiled wire, each turn of the coil contributes to the magnetic field, and the magnetic fields from the different turns add up. So the coiled wire will have a stronger magnetic field around it compared to the straight wire.

Answer:

The coiled (the loop - shaped) wire will be surrounded by the strongest magnetic field when current flows through it.