Question

An airplane in the earth’s magnetic field can develop a voltage between its wingtips.

Find this voltage if the plane has a velocity v = 250 m/s pointing due North, the earth’s magnetic field B = 0.5 G points 30◦ below due North, and the plane’s wingspan is 20 m.


Which wingtip (left or right) is at a higher electric potential?

Answer 1

Answer:

$emf=0.125\ V$

According to the Fleming's Left left hand rule we have higher potential on the right edge of the wing.

Explanation:

Given:

• velocity of plane, $v=250\ m.s^{-1}$

• magnetic field, $B=5\times 10^{-5}\ T$

• angle between velocity and magnetic field, $\theta=30^{\circ}$

• span of the wing, $l=20\ m$

We know:

$emf=B.l.v\ sin\theta$

$emf=5\times 10^{-5}\times 20\times 250\times sin30^{\circ}$

$emf=0.125\ V$

According to the Fleming's Left left hand rule we have higher potential on the right edge of the wing.