Question

The figure below shows an induction coil used to step-up voltage.

1. State the difference between the induction coil and a step-up transformer.
2. Explain how voltage is stepped up by the induction coil. 
3. The voltage is stepped up from 12V to 15kV. Determine the ratio of the secondary to primary coils in the induction coil.

Answer 1

1. State the difference between the induction coil and a step-up transformer. 
   • Sparks are produced in an induction coil but not a transformer
2. Explain how voltage is stepped up by the induction coil. 
   • The soft amateur vibrates to and fro switching on and off the current. The 1 charging magnetic flux induces e.m.f in secondary coil. The secondary has more turns and a higher e.m.f is induced.
3. The voltage is stepped up from 12V to 15kV. Determine the ratio of the secondary to primary coils in the induction coil. 
   • ^NS/_NP = ^VS/_VP = ¹⁵⁰⁰⁰/₁₂ = 1250 turns