Question

The equilibrium condition \(NIAB = C\phi\) leads to the current–deflection relationship:

Options

• \[\phi = \frac{C}{NIAB}\]

• \[\phi = \left(\frac{C}{NAB}\right)I\]

• \[\phi = \frac{NIAB}{C^2}\]

• \[\phi = \left(\frac{NAB}{C}\right)I\]

Answer 1

Solving \(NIAB = C\phi\) gives \[\phi = \left(\frac{NAB}{C}\right)I\] so the deflection is directly proportional to the current \((\phi \propto I)\). This proportionality makes the galvanometer scale linear and uniform.