In what way is the rule for interaction between magnetic poles similar to the rule for interaction between electric charges?

A step-up transformer has 50 turns in the primary coil, and 25 turns in the secondary coil. The input voltage is 90 V. What is the value of the output voltage?

A model electric train requires 6 V to operate. It is connected to a 120-V household circuit, so a transformer is needed. If the primary coil of the transformer has 220 turns, show that the secondary coil has 11 turns.

A voltage of 10 V is produced by electromagnetic induction in a coil. If the number of loops in the coil increases from 6 to 12, and the change of magnetic field with time remains the same, what is the value of voltage then produced?

A step-down transformer has an input voltage of 240 V and an output voltage of 30 V. If the current in the primary coil is 15 A, what is the value of the current in the secondary coil?