A $3-$phase, four$-$pole,$460$V$($line$-$line$).60$Hz$,$wye$-$connected induction motor has the following parameters per phase.

Ra $=0\mathrm{.}1,$ x$\text{'}$lr $=0\mathrm{.}8,$ xls $=1\mathrm{.}32,$R$\text{'}$r $=0\mathrm{.}3$

At no load $($i$.$e$.,$ slip $=0),$ the motor draws a current of $11\mathrm{.}0$ at a PF of $0\mathrm{.}87$ lagging.

For slip $=0\mathrm{.}03,$ Find the efficiency in $\%$ up to $1$ decimal place using the approximate equivalent circuit $($assuming rotational losses as $950$W$).$