The current I em units, flowing in a coil of a tangent galvanometer is given by the expression where r = Mean radius of the galvanometer coil. N = Number of turns of the galvanometer coil. H = Horizontal component of earth magnetic field. φ = Deflection of galvanometer magnetic needle.
- A. I = (Hr / 2πN)* Cosφ
- B. I = (2πNr / H)* Tanφ
- C. I = (Hr / 2πN)* Tanφ
- D. I = (2πNr / H)* Cosφ
Answer: C. I = (Hr / 2πN)* Tanφ
Explanation: Tangent law: H tanφ = 2πNI/r, so I = (Hr/2πN) tanφ.