# Respected sir,I wanted to know that why current and pressures not considered vector though they have the directions.I read in H.C.Verma that there a third necessity for a quantity to be a vector that is they should add by vector algebra or triangle method.Alright, but cant we take the addition of current and pressure as addition of two vector in same direction and hence cos theta=0.if this is no, then vectors under the condition when they r parrllel shouldnt be considered vectors.Aviral Anuragkumar TripathiArryabhatta BatchAskiitians.com

10 Points
15 years ago

Hi

u are applying a condition on a condition. The vectors are defined in such a way that they add up by vector addition , watever be the case , even if they are at angle or the same line. But in the case of current and pressure, vector addition is not valid, if u consider the currents are in same direction then u are making a wrong assumption, coz its not the case.

u add up two currents in opp direction moving to a pt, they wont be added vectorially, they 'll just add up by simple mathematics.

U'll understand this better wen u study electric circuits , parallel resistances etc.