Question

When a cell of 1.08V EMF is connected to a circuit, the current flows through it 0.5A and potential difference between the electrodes of the cell is 0.7 volt, what is the internal resistance of the cell?​

Answer 1

Given :

A cell of 1.08V EMF is connected to a circuit, the current flows through it 0.5A and potential difference between the electrodes of the cell is 0.7 volt

To Find :

Internal resistance

Solution :

$\bigstar\ \; \underbrace{\sf \pink{V=\epsilon -Ir}}$

where ,

• V denotes terminal voltage
• ε denotes EMF
• I denotes current
• r denotes internal resistance

Given ,

• V = 0.7 V
• ε = 1.08 V
• i = 0.5 A
• r = ? Ω

$:\implies \sf V=\epsilon -IR\\\\:\implies \sf 0.7=1.08-(0.5)r\\\\:\implies \sf 0.5r=1.08-0.7\\\\:\implies \sf 0.5r=0.38\\\\:\implies \sf \blue{r=0.76\ \Omega}\ \; \bigstar$

Internal resistance of the cell is 0.76 Ω

Answer 2

Answer:

Given :

A cell of 1.08V EMF is connected to a circuit, the current flows through it 0.5A and potential difference between the electrodes of the cell is 0.7 volt

To Find :

Internal resistance

Solution :

\bigstar\ \; \underbrace{\sf \pink{V=\epsilon -Ir}}★

V=ϵ−Ir

where ,

V denotes terminal voltage

ε denotes EMF

I denotes current

r denotes internal resistance

Given ,

V = 0.7 V

ε = 1.08 V

i = 0.5 A

r = ? Ω

\begin{gathered}:\implies \sf V=\epsilon -IR\\\\:\implies \sf 0.7=1.08-(0.5)r\\\\:\implies \sf 0.5r=1.08-0.7\\\\:\implies \sf 0.5r=0.38\\\\:\implies \sf \blue{r=0.76\ \text{\O}mega}\ \; \bigstar\end{gathered}

:⟹V=ϵ−IR

:⟹0.7=1.08−(0.5)r

:⟹0.5r=1.08−0.7

:⟹0.5r=0.38

:⟹r=0.76 Ømega ★

Internal resistance of the cell is 0.76 Ω