Potentiometer Apparatus
Product Code : SCL-EAE-11258
Quick answer: The Potentiometer Apparatus measures potential difference by the null method along a uniform resistance wire. Students find the balance length at which the galvanometer shows no deflection and use it to compare the EMFs of two cells or to find the internal resistance of a cell. Lab Exports manufactures it in Delhi for schools, colleges and universities.
Specifications
| Parameter | Detail |
|---|---|
| Primary function | EMF comparison and null-deflection experiments |
| Principle | Potential gradient and balance-length method |
| Category | Physics laboratory equipment, electrical |
Wire length, scale range and supplied accessories are not listed on this page; email [email protected] with the house code for the current configuration.
How the potentiometer experiment is done
A steady current from a driver cell flows through a uniform resistance wire, so the potential falls evenly along it; the fall per unit length is the potential gradient k. A cell connected against the wire through a galvanometer shows no deflection at the balance length l where its EMF equals k l. Because no current is drawn from the cell at balance, the potentiometer measures the true EMF, unlike a voltmeter.
- Place the apparatus on a dry bench and inspect the wire and terminals.
- Connect the wire to the driver circuit through a low-voltage source, a key and a rheostat.
- Connect the cell under test, like poles joined at the same end, through a galvanometer to the jockey.
- Slide the jockey along the wire, tapping lightly, until the galvanometer shows no deflection, and note the balance length.
- For two cells, E1/E2 = l1/l2; for internal resistance, r = R (l1 - l2)/l2 with a known resistance R across the cell.
Key features
- Null-deflection method: the balance point is found without drawing current from the cell
- Compares the EMFs of two cells from their balance lengths
- Finds the internal resistance of a primary cell
- Relates potential difference to the length of resistance wire used
- Hands-on practice in circuit assembly and jockey contact
- Suits guided practicals and laboratory assessments
Documentation and supply
Most Lab Exports products carry a one-year manufacturer warranty.
Lab Exports manufactures the potentiometer apparatus at its works in Laxmi Nagar, Delhi, and supplies it to schools, colleges and universities in India and 60+ countries, handling the export documents for each shipment. More about the company is on the About Lab Exports page.
Related Electrical and Electronics products
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- Step Down Transformer (SCL-EAE-11259)
- Resistance Coil (SCL-EAE-11260)
- Leclanche Cell 1.5V (SCL-EAE-11261)
- Resistance Coil Unit (SCL-EAE-11262)
- Daniel Cell (SCL-EAE-11263)
The full range is in the Electrical and Electronics section of the Physics Lab range.
Frequently asked questions
Why is a potentiometer better than a voltmeter for measuring EMF?
At the balance point no current flows from the cell under test, so there is no voltage drop across its internal resistance and the true EMF is measured.
How are two EMFs compared with the potentiometer?
Find the balance length for each cell with the same driver current; the ratio of the EMFs equals the ratio of the balance lengths, E1/E2 = l1/l2.
What is the price of the potentiometer apparatus?
Prices are not published on the website. Add the potentiometer apparatus to the Enquiry Cart with the Add To Cart button on this page, or email [email protected] with the house code SCL-EAE-11258 and the quantity, to receive a quotation.
Does Lab Exports manufacture the potentiometer apparatus?
Yes. Lab Exports manufactures the potentiometer apparatus at its works at 11/315, Lalita Park, Laxmi Nagar, Delhi 110092, under house code SCL-EAE-11258.
Request a quote
Email [email protected] with the house code SCL-EAE-11258 and the quantity, or add the potentiometer apparatus to the Enquiry Cart with the Add To Cart button on this page. Tender buyers can also see the Tenders and OEM page.
