NTA Abhyas JEE Main2020PhysicsAlternating CurrentPractice
A power transmission line feeds input power at 2400   V to a step-down transformer and which delivers power at 240   V with its primary windings having 5000 turns. If the current in the primary coil of the transformer is 5   A and its efficiency is 80 % , then what is the output current (in A )?
Correct answer
40
Step-by-step solution
ε p = 2400 V , N p = 5000 ε s = 240 V , I p = 5 A efficiency, η = 80 % = 0 . 8 , I s = ? η = P 0 P i = ε s I s ε p I p ⇒ I s = η ε p I p ε s = 0 . 8 × 2400 × 5 240 = 40 A