actually in a roundabout way it can be..depending on definitions.....with excess amounts of runway available, it is quite often possible for a jet aircraft to have the ability to stop after Vr is reached, and a rotation is accomplished..especially at light weights...however, a rejected takeoff is statisticaly more likely to result in an accident, than a take-off continued...but a good example is the Detroit runway collision between a NWA B-727 and a NWA DC-9 who entered the runway mistakenly the 727 had actually begun his rotation when his wing collided with the forward fuselage of the dc-9...the 727 capt discontinued the take-off and stopped in the remaining runway...his left wing was so severely damaged, that a successful continued take-off, and flight would have not been successful...to answer the original question...when the available runway length exceeds the balanced field length requirement for an aircraft, V1 may well be a higher speed than Vr...but go to your local expert before taking your exam..FAA balanced field length=
1) distance to accelerate to V1 then stop
2) distance to accelerate to V1 lose an engine and attain a height of 35 feet
3) 1.15 times the two engine take-off distance to 35 feet..cheers