When a current of 2,A flows in a battery from | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) Let $E$ be the emf and $r$ be the internal resistance of the battery.When current $I = 2\,A$ flows from negative to positive terminal (charging),t

Vedclass · Accepted Answer

$13.2$

Vedclass · Answer

(B) Let $E$ be the emf and $r$ be the internal resistance of the battery.When current $I = 2\,A$ flows from negative to positive terminal (charging),the terminal potential difference is given by $V = E + Ir$.$12 = E + 2r$  ..........$(1)$When current $I = 3\,A$ flows in the opposite direction (discharging),the terminal potential difference is given by $V = E - Ir$.$15 = E - 3r$  ..........$(2)$Wait,let's re-evaluate the conditions: If current flows from negative to positive,it is charging: $V = E + Ir = 12$.If current flows from positive to negative,it is discharging: $V = E - Ir = 15$.Subtracting $(2)$ from $(1)$: $(E + 2r) - (E - 3r) = 12 - 15 \Rightarrow 5r = -3$. This implies a sign convention issue in the problem statement. Let's assume standard convention: Case $1$: $V = E - Ir = 12$ for $I = 2\,A \Rightarrow E - 2r = 12$.Case $2$: $V = E + Ir = 15$ for $I = 3\,A \Rightarrow E + 3r = 15$.Adding the two equations: $(E - 2r) + (E + 3r) = 12 + 15 \Rightarrow 2E + r = 27$.Multiplying $(1)$ by $3$ and $(2)$ by $2$: $3E - 6r = 36$ and $2E + 6r = 30$.Adding these: $5E = 66 \Rightarrow E = 13.2\,V$.

When a current of $2\,A$ flows in a battery from negative to positive terminal,the potential difference across it is $12\,V$. If a current of $3\,A$ flows in the opposite direction,the potential difference across the terminals of the battery is $15\,V$. The emf of the battery is ............... $V$.

Similar Questions

Identify $A$ in the following reaction.
$A + \text{Acetic anhydride} \xrightarrow{H^{+}} \text{Aspirin} + \text{Acetic acid}$

The image of the point $(1, 2, -1)$ on the plane containing the line $\frac{x+1}{-3}=\frac{y-3}{2}=\frac{z+2}{1}$ and the point $(0, 7, -7)$ is:

Which of the following molecules has a zero dipole moment?

$A$ gamma ray photon creates an electron-positron pair. If the rest mass energy of an electron is $0.5\, MeV$ and the total kinetic energy of the electron-positron pair is $0.78\, MeV$,then the energy of the gamma ray photon must be $......\, MeV$.

The figure shows the experimentally measured $B$ vs $H$ variation in a ferromagnetic material. The values of retentivity,coercivity,and saturation magnetic field of the material are respectively:

Vedclass Test Series

Exam Paper Generator

Online Exam Module