Vicarious Liability Ka Maze - Section 140 of the IPC

Abhi toh main yeha khichdi samajh nahi paa raha. So, Section 140 of the IPC says that the liability of a principal is only up to the extent of the act done by the agent. Toh agar agent ki neechaatya 5000 rs hai aur principal ne apne bhai se 10000 rs ki aadat lagayi, toh principal ka liability 5000 rs hi rahega? Par Section 141 kehne kee cheezein bhi hi hain ki principal ka pata hona chaahiye ki agent kya kar raha hai. Toh kya ye donon sections ek dusre se judh jati hain? Kya yeh Section 140 ke liye bhi lid lagata hai? Main to samajh nahi paya.