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#DC circuit

2 public questions tagged with this topic.

AC Generator, Back EMF and Time Duration of EMF

A coil is connected to a DC source via a switch. When the switch is opened, a spark is observed. This is due to what phe

**AC generator** emf e = N B A ω sin ωt, maximum when coil plane parallel to field, zero when perpendicular, time duration of emf when loop moves out of field t = L/v, L side along motion, v speed, e = B l v while cutting. For loop 0.28×0.14 m B=0.3 T v=1.4 m/s along longer side 0.28 m, cutting side 0.14 m, e=0.3×0.14×1.4=0.0588 V, duration t=0.28/1.4=0.2 s, emf exists only during exit. Opening the switch causes a rapid decrease in current, inducing a high back emf due to self-inductance, which can cause a spark as the energy dissipates. Using Φ = B A

Ref: NCERT > Physics Book > Electromagnetic Induction > AC Generator, Back EMF and Time Duration of EMF

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AC Generator, Back EMF and Time Duration of EMF

A coil connected to a DC source shows a slow rise in current when switched on. This delay is primarily due to what effec

**AC generator** emf e = N B A ω sin ωt, maximum when coil plane parallel to field, zero when perpendicular, time duration of emf when loop moves out of field t = L/v, L side along motion, v speed, e = B l v while cutting. For loop 0.28×0.14 m B=0.3 T v=1.4 m/s along longer side 0.28 m, cutting side 0.14 m, e=0.3×0.14×1.4=0.0588 V, duration t=0.28/1.4=0.2 s, emf exists only during exit. Self-inductance induces a back emf that opposes the current increase, causing a gradual rise until the steady state is reached. Using Φ = B A cosθ, e = -N dΦ/dt =

Ref: NCERT > Physics Book > Electromagnetic Induction > AC Generator, Back EMF and Time Duration of EMF

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