A_galvanometer_based_recorder_works_on_the_principle_of_________$

• A. Van der Wall‚Äö√Ñ√∂‚àö√ë‚àö¬•s effect
• B. D‚Äö√Ñ√∂‚àö√ë‚àö¬•Arsonval movement
• C. Paschen effect
• D. Azhimuthal quatum number