Question

A jet plane is travelling west at the speed of $1600km{h}^{-1}$. The voltage difference developed between the ends of the wing having a span of $20m$, if the earth’s magnetic field at the location has a magnitude of $5\times 10^{-4}T$ and the dip angle is $30^{\circ }$ is

• A. $4.1V$
• B. $2.2V$
• C. $3.2V$
• D. $3.8V$

Answer 1

Answer: (B)

Here, $v=1600km{h}^{-1}$
$=1600\times \frac{5}{18}=444m{s}^{-1}$
$l=20m$,
$B=5\times 10^{-4}T$ and $\delta =30^{\circ }$
As $\epsilon =Blv=Vlv$
(where $V$ is the vertical component of earths field)
$=\left(Bsin\delta \right)lv$ $\left(\because V=Bsin\delta \right)$
$=5\times 10^{-4}sin30^{\circ }\times 20\times 444$
$=2.2V$