An Unusual Lightning Strike Has a Vertical Portion with a Positive

question 67

Multiple Choice

An unusual lightning strike has a vertical portion with a positive current of +400 A upwards. The Earth's magnetic field at that location is parallel to the ground and has a magnitude of 30 μT. In N, the force exerted by the Earth's magnetic field on the 25 m-long current is

• A) 0.
• B) 0.012 N, East.
• C) 0.012 N, West.
• D) 0.30 N, West.
• E) 300 N, East.