Asked in NUMS 2019 (cancelled sitting) 2019Moderate

An aircraft of wingspan 50 m flies horizontally at an area where the vertical component of the Earth's magnetic field is 2.0 x 10^-5T. In order to produce an emf of 1 volt between the aircraft's wingtips, its speed should be:

Correct answer: A. 1000 m/s

  • A. 1000 m/s
  • B. 500 m/s
  • C. 100 m/s
  • D. 15000 m/s
  • E. 250000 m/s

Explanation

The emf induced in a conductor moving with a velocity 'v' perpendicular to a magnetic field 'B' is given by the equation: emf = BvL where 'L' is the length of the conductor. In this case, the wingspan of the aircraft is 'L,' and the vertical component of the Earth's magnetic field is 'B'. Therefore, the emf induced between the wingtips is: emf = BvL The emf required to produce 1 volt is given as: emf = 1 volt Substituting the given values, we get: 1 volt = (2.0 x 10^-5 T) x (50 m) x v Solving for 'v', we get: v = 1000 m/s Therefore, the speed of the aircraft should be 1000 m/s to produce an emf of 1 volt between its wingtips.

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