Why does a torque rod have a stronger magnetic field than a torque coil?

Magnetic torquer or torque rod are essentially sets of electromagnets that are laid out to create a magnetic field that interfaces with an ambient magnetic field, so that the counter-forces produced is a stronger magnetic force. In addition, its magnetic field strength increases with the current due to the rod that has field lines pointing in the same direction, closed together and nearly parallel with uniformly spaced. This set up indicates that the field of a torque rod produced powerful magnetic field than a torque coil.

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