Question

Current $I$ is being driven through a cell of emf $E$ and internal resistance $r$ as shown in the figure. Choose the following correct statements.

• A. The cell absorbs energy at the rate of $EI$
• B. The cell stores chemical energy at the rate of $(EI-I^{2}r)$
• C. The potential difference across the cell is $E+Ir$
• D. Some heat is produced in the cell

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A The cell stores chemical energy at the rate of $(EI-I^{2}r)$
B The cell absorbs energy at the rate of $EI$
C Some heat is produced in the cell
D The potential difference across the cell is $E+Ir$

Rate of absorption of energy is power of the battery

$P=IV$

$P=EI$

The potential difference across the cell

$\Delta V=E-Ir$

So, power = $I(E-Ir)=EI-I^{2}r$

$V_A+Ir+E=V_B$

$V_B-V_A=E+Ir$

As there is resistance in the cell, so it must generate heat as,

$H=I^{2}R$