Question 625: Current Electricity

Question

The emf of a cell having internal resistance $$1 \Omega$$ is balanced against a length of $$330 \mathrm{~cm}$$ on a potentiometer wire. When an external resistance of $$2 \Omega$$ is connected across the cell, the balancing length will be :

Accepted Answer

$$\begin{aligned} & \mathrm{r}=\left(\frac{\ell_{\mathrm{o}}-\ell_{\mathrm{c}}}{\ell_{\mathrm{c}}}ight) \mathrm{R} \ & 1=\left(\frac{330-\ell_{\mathrm{c}}}{\ell_{\mathrm{c}}}ight) 	imes 2 \ & 3 \ell_{\mathrm{c}}=660 \ & \ell_{\mathrm{c}}=220 \mathrm{~cm}\end{aligned}$$

Answer

220 cm

Answer

330 cm

Answer

115 cm

Answer

332 cm

Current Electricity

The emf of a cell having internal resistance $1 \Omega is balanced against a length of 330 \mathrm{~cm} on a potentiometer wire. When an external resistance of 2 \Omega$ is connected across the cell, the balancing length will be :

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