A generator develops an e.m.f of 150 V and has a terminal potential difference of 125 V, when the armature current is 50 A, the resistance of armature will be
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \( 0.5\,\Omega \)
A generator behaves like a cell with an emf E and an internal (armature) resistance R. Part of the emf is lost as the voltage drop \( IR \) inside the armature, so the terminal potential difference is \( V = E - IR \).
\( \displaystyle R = \frac{E - V}{I} = \frac{150\,\mathrm{V} - 125\,\mathrm{V}}{50\,\mathrm{A}} = 0.5\,\Omega \)