If current flow increases, what happens to the magnetic field?

If current flow increases, what happens to the magnetic field?

• A. It decreases.
• B. It increases.
• C. It remains unchanged.
• D. It oscillates unpredictably.

Answer: (B)

The magnetic field strength produced by an electric current grows with how much current is flowing. Moving charges create the field, and its magnitude is proportional to the current. For a long straight wire, the field at a given distance is B = μ0 I / (2πr); for a coil or solenoid, B is proportional to I as well. So when current increases, the magnetic field becomes stronger (double the current gives roughly double the field at the same location). The direction follows the right-hand rule, but the question is about strength, so the correct idea is that the magnetic field increases with current. The other options—decreasing, staying the same, or oscillating unpredictably—do not align with this straightforward proportional relationship for steady current.

The magnetic field strength produced by an electric current grows with how much current is flowing. Moving charges create the field, and its magnitude is proportional to the current. For a long straight wire, the field at a given distance is B = μ0 I / (2πr); for a coil or solenoid, B is proportional to I as well. So when current increases, the magnetic field becomes stronger (double the current gives roughly double the field at the same location). The direction follows the right-hand rule, but the question is about strength, so the correct idea is that the magnetic field increases with current. The other options—decreasing, staying the same, or oscillating unpredictably—do not align with this straightforward proportional relationship for steady current.