Question

An aircraft with a wing span of $40\text{m}$ flies with a speed of $1080{\text{km-hr}}^{-1}$ in the eastward direction at a constant altitude in the Northern Hemisphere, where the vertical component of earth's magnetic field is $1.75\times {10}^{-5}\text{T}$. Find the emf that develops across the tips of the wings.

• A. $4.25\text{V}$
• B. $2.12\text{V}$
• C. $0.21\text{V}$
• D. $2.75\text{V}$

Answer 1

The correct option is C $0.21\text{V}$

The metallic part between the wing-tips can be treated as a single conductor (like a thin uniform rod) cutting flux-lines due to the vertical component of earth's magnetic field.

So, emf is induced between the tips of its wings.

$\epsilon =vBl=1080\times \frac{5}{18}\times 1.75\times {10}^{-5}\times 40=0.21\text{V}$

Hence, option $\left(C\right)$ is the correct answer.