The term "magnetic effects of current "  means that " a current flowing in a wire produces a magnetic field round it ". the magnetic effect of current was discovered by Oersted found that a wire carrying a current was able to deflect a magnetic needle. It concludes that a current flowing in a wire always gives rise to a magnetic field round it, the electric motor, telephone and radio, all utilize the magnetic effect of current .

       

    Click here for Oersted's Experiment