A researcher would like to perform an experiment in a zero magnetic field, which means that the field of the earth must be canceled. Suppose the experiment is done inside a solenoid of diameter 1.0 m, length 4.6 m , with a total of 5000 turns of wire. The solenoid is oriented to produce a field that opposes and exactly cancels the 52 Î¼T local value of the earth’s field.

What current is needed in the solenoid’s wires?

Express your answer to two significant figures and include the appropriate units.

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Answer:I = 3.81 x 10⁴ A

Explanation:The magnetic field of a solenoid must be equal to the field of earth:

where,

I = current passing through solenoid = ?

μ = permeability of free space = 4π x 10⁻⁷ N/A²

n = no. of turns per unit length = = 1086.96 /m

Therefore,

I = 3.81 x 10⁴ A