MHT CET202415 May 2024Evening ShiftPhysicsElectromagnetic InductionActual
A metal disc of radius R rotates with an angular velocity about an axis perpendicular to its plane passing through its centre in a magnetic field of induction B acting perpendicular to the plane of the disc. The induced e.m.f. between the rim and axis of the disc is .
Options
- AB R ^2
- B2 B ^2 R ^2
- CB R ^2
- DBR ^2 2
Correct answer
D. BR ^2 2
Step-by-step solution
aligned & Induced e.m.f., & aligned e & = - d dt =- d ( BA ) dt & =- B dA dt .( B = constant ) aligned aligned Area swept between axis and the rim, dA = R ^2 Time during which the change in flux taking place, dt = 2 aligned & e= -B R^2 2 / = -B R^2 2 & |e|= B R^2 2 aligned