Potentiometer: emf comparison, internal resistance
A long wire with a driver cell: find null points for two cells to get E₁/E₂ = l₁/l₂ and use a shunt resistance across a cell to find its internal resistance r = R(l₁ − l₂)/l₂.
About this experiment
| Subject | Physics |
|---|---|
| Class | 12 |
| Chapter | 3. Current Electricity |
| NCERT section | 3.13 |
| Level | NCERT level |
| Time | about 12 minutes |
| Access | Included in a PractiSci plan |
What you do in the lab
Change the controls and watch the physics behave in real time in 3D. Live readouts and graphs show the numbers behind it, and the Learn tab has the theory, procedure, observations and viva questions. Works on a phone or a laptop, in English and Hindi.
Topics: potentiometer · null method · emf comparison · internal resistance · potential gradient
More from this chapter
- Internal resistance of a cell, combination of cells
- Drift velocity of electrons in a conductor
- Galvanometer: resistance and figure of merit (half-deflection)
- Kirchhoff's laws on circuits
- Metre bridge and Wheatstone bridge
- Ohm's law: V–I characteristics
- Resistivity and temperature dependence of a wire
- Resistor colour code and series/parallel combinations