Question

State one factor that determines the magnitude of induced e.m.f.

Answer 1

The Faraday's laws of electromagnetic induction says that the E.M.F. induced in a coil 'e' = -(rate of change of magnetic flux linkage)

where,
the Flux linkage =number of turns'N' x magnetic field'B' x area'A' x cos$\theta$
where,
theta is angle between magnetic field B and area A.
Theta at any instant 't'=$\left(angularvelocit{y}^{\prime }{w}^{\prime }\right)\times \left(timeinstan{t}^{\prime }{t}^{\prime }\right)$.

That is, Theta = $w\times t$.

E.M.F. induced in a coil 'e'=$N\times B\times A\times w\times sinw\times t$.
The factors involved in the induced emf of a coil are:

• The induced e.m.f. is directly proportional to N, the total number of turns in the coil.
• The induced e.m.f. is directly proportional to A, the area of cross-section of the coil.
• The induced e.m.f. is directly proportional to B, the strength of the magnetic field in which the coil is rotating.
• The induced e.m.f. is directly proportional to 'w', the angular velocity of coil.
• The induced e.m.f. also varies with time and depends on instant 't'.
• The induced e.m.f. is maximum when plane of coil is parallel to magnetic field B and e.m.f. is zero when plane of coil is perpendicular to magnetic field B.