Question

A metal conductor of length $1 \,m$ rotates vertically about one of its ends with an angular velocity $5 \,rad\, s^{-1}$. If the horizontal component of earths magnetic field is $0.2 \times10^{-4}\,T$, then the emf developed between the ends of the conductor is

• A. $5\, \mu\,V$
• B. $5\,m\,V$
• C. $50\, \mu \, V$
• D. $50\,m\,V$

Answer 1

The Correct Option is C

The emf developed between the ends of the conductor is
$\varepsilon=\frac{1}{2}\omega Bl^{2}=\frac{1}{2}\times5\times0.2\times10^{-4}\times(1)^{2}$
$=5\times10^{-5}\,V=50\times10^{-6}V$
$=50\, \mu\,V$