Force between two parallel currentsदो समांतर धाराओं के बीच बलForce between two parallel currents

NCERT Fig 4.17 · Class 12 Physics · Chapter 4 · interactive diagram

Parts and what they mean

• Conductor a, current Ia (चालक a, धारा Ia) — Makes a field Ba = μ₀Ia/2πd at conductor b.
• Conductor b, current Ib (चालक b, धारा Ib) — Sits in the field of a and feels F = Ib L Ba.
• Current Ia (upwards) (धारा Ia (ऊपर)) — Steady current in a.
• Current Ib (upwards) (धारा Ib (ऊपर)) — Same direction as Ia in (a).
• Ba: field of a at b — into the page (Ba: b पर a का क्षेत्र — पृष्ठ के अंदर) — Right-hand rule for wire a: to its right the field goes into the page.
• Fba: force on b, towards a (Fba: b पर बल, a की ओर) — Ib (up) × Ba (into page) points left, towards a. Fba = μ₀IaIbL/2πd.
• Fab: force on a, towards b (Fab: a पर बल, b की ओर) — Equal and opposite: Fab = −Fba (Newton’s third law).
• Separation d (दूरी d) — Force per unit length f = μ₀IaIb/2πd.
• Conductor a (current up) (चालक a (धारा ऊपर)) — Now the currents are antiparallel.
• Conductor b (current down) (चालक b (धारा नीचे)) — Its field at a is out of the page (⊙).
• Force on b: away from a (b पर बल: a से दूर) — Ib (down) × Ba (into page) points right: repulsion.
• Force on a: away from b (a पर बल: b से दूर) — Antiparallel currents repel.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 4.17. Report a mistake