The formula for the magnetic field inside an ideal long solenoid is B = μ₀ n I, where μ₀ is the permeability of free space, n is the number of turns per unit length, and I is the current. If the number of turns per unit length is increased to 2n while the current I remains the same, the new magnetic field B' will be B' = μ₀ (2n) I = 2 (μ₀ n I).
In a solenoid, the current flowing through the wire is I and number of turns per unit length is n. This gives a magnetic field B inside the solenoid. If number of turn per unit length is increased to 2n, what will be the value of magnetic field in the solenoid?
Asked in UPSC NDA 1 2017 · Topic: Electric Current (Ohm's Law, resistance, resistivity, and conductivity)
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