ELM-008 · Magnetism and electromagnetic induction Sample material

Current in liquids and gases. The magnetic field of a current

Electric current in electrolytes and Faraday's laws of electrolysis, non-self-sustained and self-sustained gas discharges, the magnetic field of a direct current, the magnetic induction vector, the Biot–Savart–Laplace law and the fields of straight and circular currents.

Estimated time: 3 h 5 activities

Learning objective

Explain electrolytic dissociation and the nature of charge carriers in electrolytes.
Derive Faraday's laws of electrolysis and apply them to problems.
Study the mechanism and types of non-self-sustained and self-sustained gas discharges.
Master magnetic induction, magnetic field strength and the Biot–Savart–Laplace law, and calculate the fields of straight and circular currents.

Expected outcomes

Can calculate the mass of substance liberated in electrolysis, the required charge and time.
Can explain the current–voltage characteristic of a discharge and distinguish types of self-sustained discharge.
Can calculate the magnetic induction of a straight current, at the centre of a loop and inside a solenoid.
Can add the fields of several currents by superposition and find the direction of B with the right-hand screw rule.

Interactive modelElectrolysis and Faraday's laws
Interactive modelMagnetic field of a current

Activities

Lecture
Lecture · 1 h 20 min · required
Problems on electric current in liquids and gases. Solving problems on the magnetic interaction of currents
Practice · 1 h 20 min · required
Determination of the electrochemical equivalent of copper
Laboratory · 1 h 20 min · optional
The Biot–Savart–Laplace formula
Self-study · 6 h · optional
Final test
Test · 20 min · required · pass ≥ 70%

Completion conditions

  • Lecture
  • Problems on electric current in liquids and gases. Solving problems on the magnetic interaction of currents
  • Final test — at least 70%