A battery has an emf of 15 V and internal resistance of 1 Ω . Is the terminal to terminal potential difference less than, equal to or greater than 15 V if the current in the battery is (1) from negative to positive terminal, (2) from positive to negative terminal (3) zero current ?

Question

A battery has an emf of 15 V and internal resistance of 1 Ω . Is the terminal to terminal potential difference less than, equal to or greater than 15 V if the current in the battery is (1) from negative to positive terminal, (2) from positive to negative terminal (3) zero current ? (A) Less, greater, equal (B) Less, less, equal (C) Greater, greater, equal (D) Greater, less, equal

Tardigrade Admin · Accepted Answer

If E is the emf of the battery, r the internal resistance, i the current drawn and V the PD across the plates of battery, then V = E -ir Case I: When the direction of current in the battery is from −ve to + ve or outside + ve to −ve, then i = + ve (during discharging) V = E + ir Case II: When the direction of current in the battery is from + ve to −ve or outside −ve to +ve, then i = − ve (during charging) V = E + ir ⇒ V > E Case III: When zero current, then i = 0 V = E

Q. A battery has an emf of 15V and internal resistance of 1Ω . Is the terminal to terminal potential difference less than, equal to or greater than 15V if the current in the battery is (1) from negative to positive terminal, (2) from positive to negative terminal (3) zero current ?

Less, greater, equal

Less, less, equal

Greater, greater, equal

Greater, less, equal

Q. A battery has an emf of $15 V$ and internal resistance of $1Ω$ . Is the terminal to terminal potential difference less than, equal to or greater than $15 V$ if the current in the battery is $(1)$ from negative to positive terminal, $(2)$ from positive to negative terminal $(3)$ zero current ?