Question

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

• A. $3.8\text{V}$
• B. $3.2\text{V}$
• C. $2.2\text{V}$
• D. $4.1\text{V}$

Answer 1

The correct option is C $2.2\text{V}$

Given, $B=5\times {10}^{-4}\text{T};l=20\text{m}v=1600\text{kmph};\theta ={30}^{\circ }$

Assuming the plane as a conductor, the induced emf is,

$E=B_{v}lv=Blv\sin \theta [\because B_v=B\sin \theta ]$

$=5\times {10}^{-4}\times 20\times 1600\times \frac{5}{18}\times \sin {30}^{\circ }$

$=\frac{40}{18}=2.2\text{V}$

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, $\left(C\right)$ is the correct answer.