NEETPhysicsCurrent ElectricityMCQ+4 / −1
The emf of a cell having internal resistance is balanced against a length of on a potentiometer wire. When an external resistance of is connected across the cell, the balancing length will be :
- A220 cm
- B330 cm
- C115 cm
- D332 cm
View written solutionFree
Correct answer: A
$$\begin{aligned} & \mathrm{r}=\left(\frac{\ell_{\mathrm{o}}-\ell_{\mathrm{c}}}{\ell_{\mathrm{c}}}\right) \mathrm{R} \\ & 1=\left(\frac{330-\ell_{\mathrm{c}}}{\ell_{\mathrm{c}}}\right) \times 2 \\ & 3 \ell_{\mathrm{c}}=660 \\ & \ell_{\mathrm{c}}=220 \mathrm{~cm}\end{aligned}$$
More from Current Electricity
- The magnitude and direction of the current in the following circuit is :- Includes diagram2023 · MCQ
- If the galvanometer does not show any deflection in the circuit shown, the value of is given by: Includes diagram2023 · MCQ
- Resistance of a carbon resistor determined from colour codes is . The colour of third band must be :2023 · MCQ
- The resistance of platinum wire at is and at . The temperature coefficient of resistance of the wire is :2023 · MCQ
- 10 resistors, each of resistance are connected in series to a battery of emf and negligible internal resistance. Then those are connected in parallel to the same battery, the current is increased times. The value of…2023 · MCQ
- The reciprocal of resistance is :2022 · MCQ
- A cell of emf 4 V and internal resistance 0.5 is connected to a 7.5 external resistance. The terminal potential difference of the cell is2022 · MCQ
- The equivalent resistance of the infinite network given below is : Includes diagram2022 · MCQ