I don't think we had to subtract anything. Afterall it was for only a mark, and I think there would have been a mark reserved for the subtraction, making it a 2 mark question.117for me ...I was confused when it was of 1 mark?
Wht abtr tht efficiency question wht do u reckon wud be th 2 marks/2 points?
I wrote percentage of input energy converted in to useful output energy, and also mentioned the formula