Question

Two moving coil galvanometers `1` and `2` are with identical field magnets and suspension torque constants, but with coil of different number of turns `N_(1)` and `N_(2)`, area per turn `A_(1)` and `A_(2)`, and resistance `R_(1)` and `R_(2)`. When they are connected in series in the same circuit, they show deflections `theta_(1)` and `theta_(2)`. then `theta_(1)//theta_(2)` is
A. `A_(1) N_(1)// A_(2) N_(2)`
B. `A_(1) N_(2)// A_(2) N_(1)`
C. `A_(1) R_(2) N_(1)// A_(2) R_(2) N_(2)`
D. `A_(1)R_(1) N_(1)// A_(2)R_(2) N_(2)`

Answer 1

Correct Answer - A
`I = (k)/(NBA) 6.` Given that `I_(1) = I_(2)`
`:. (K theta_(1))/(N_(1)BA_(1)) = (K theta_(2))/(N_(2)BA_(2))`
So `(theta_(1))/(theta_(2)) = (A_(1)N_(1))/(A_(2) N_(2))`