A metal rod of length 0.5 m is placed normal to a uniform magnetic field 1.2 T and moved with a velocity 10 cm/s perpendicular to the field. The induced emf across the ends of the rod is
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 60 mV
A rod moving through a magnetic field has a motional emf across its ends. Here the rod, the field and the velocity are mutually perpendicular, so
\( \displaystyle \varepsilon = Blv \)
\( B = 1.2\,\mathrm{T} \)
\( l = 0.5\,\mathrm{m} \)
\( v = 10\,\mathrm{cm\,s^{-1}} = 0.1\,\mathrm{m\,s^{-1}} \)
\( \displaystyle \varepsilon = 1.2\,\mathrm{T} \times 0.5\,\mathrm{m} \times 0.1\,\mathrm{m\,s^{-1}} \)
\( \displaystyle \varepsilon = 0.06\,\mathrm{V} = 60\,\mathrm{mV} \)