A step -down transformed with and efficiency of $80 \%$ is used on a 1000 V line to deliver 10 A at

Question

A step -down transformed with and efficiency of $80 \%$ is used on a 1000 V line to deliver 10 A at 100 V at the secondary coil. The current drawn from the line is\

Professor PC Thomas Classes · Answer

\.Efficiency of transformer\ $=\frac{	ext { Energy obtained from thescondary coil }}{	ext { Energy given to the primary coil }}$ $$ \eta=\frac{V_{S} I_{S}}{V_{P} I_{S}} \frac{80}{100}=\frac{10 	imes 100}{1000 	imes I_{p}} \Rightarrow I_{P}=\frac{100}{80}=1.25 A $$