The potential difference between the terminals of a cell in open circuit is 2.2 V. With resistance of 5 Ω across the terminals of a cell, the terminal potential difference is 1.8 V. The internal resistance of the cell is

Question

The potential difference between the terminals of a cell in open circuit is 2.2 V. With resistance of 5 Ω across the terminals of a cell, the terminal potential difference is 1.8 V. The internal resistance of the cell is (A) (7/12)Ω (B) (12/7)Ω (C) (9/10)Ω (D) (10/9)Ω

Tardigrade Admin · Accepted Answer

V =(ER/R + r) = (2.2 × 5/5 + r) = 1.8 i.e. r = (10/9) Ω

Q. The potential difference between the terminals of a cell in open circuit is 2.2 V. With resistance of $5 Ω$ across the terminals of a cell, the terminal potential difference is 1.8 V. The internal resistance of the cell is

$\frac{7}{12} Ω$

$\frac{12}{7} Ω$

$\frac{9}{10} Ω$

$\frac{10}{9} Ω$

V = $\frac{ER}{R + r} = \frac{2.2 \times 5}{5 + r}$ = 1.8 $i . e . r = \frac{10}{9} Ω$

Q. The potential difference between the terminals of a cell in open circuit is 2.2 V. With resistance of 5Ω across the terminals of a cell, the terminal potential difference is 1.8 V. The internal resistance of the cell is

127​Ω

712​Ω

109​Ω

910​Ω