Question

A 0.4 m long straight conductor moves in a magnetic field of magnetic induction $0.9\,Wb/m^{-2}$ with a velocity of 7m/s. Calculate the e.m.f. induced in the conductor under the condition when it is maximum.

• A. 2V
• B. 2.52 V
• C. 5.22 V
• D. 3.5 V

Answer 1

Answer: (B)

Flux linked with area generated by the motion of conductor in time t is given by $\phi= Bl (v\, \sin\, \theta) t$
Induced $e.m .f., \varepsilon = \frac{d\phi}{dt} = \frac{d}{dt} Bl ( v \, \sin \, \theta)$
E is maximum when sin $\theta$ = 1 $i.e.$ when rod moves normal to its length, $\therefore $ $\varepsilon_{max} = B/v$
= $0.9 \times 0.4 \times 7 = 2.52$ V