Can the Luminous Flux Transmitted by Object be negative?
No, the Luminous Flux Transmitted by Object, measured in Luminous Flux cannot be negative.
What unit is used to measure Luminous Flux Transmitted by Object?
Luminous Flux Transmitted by Object is usually measured using the Lumen[lm] for Luminous Flux. Candela Steradian[lm], Lux Square Meter[lm] are the few other units in which Luminous Flux Transmitted by Object can be measured.