Tangent Galvanometer
Product Code : SCL-M-11272
Quick answer: A tangent galvanometer is a circular coil with a compass box at its centre, used to verify the tangent law and to find current from the deflection of a magnetic needle set in the magnetic meridian. It works on the magnetic effect of electric current, read on an angular scale. Lab Exports manufactures it in Delhi for schools, colleges and universities.
Specifications
| Parameter | Detail |
|---|---|
| Operating principle | Tangent law and the magnetic effect of electric current |
| Measuring element | Compass needle with angular scale |
| Arrangement | Circular current-carrying coil with the compass box near its centre |
| Typical experiments | Tangent law, reduction factor, current from deflection, horizontal component of the Earth's field |
Coil diameter, number of turns, terminal arrangement and scale graduation are confirmed with the quotation for the supplied model.
How the tangent galvanometer experiment is done
A current I through a circular coil of n turns and radius r sets up a field B = mu0 n I / (2r) at its centre, perpendicular to the plane of the coil. With the coil set in the magnetic meridian, this field acts at right angles to the horizontal component of the Earth's field, BH, and the needle comes to rest at an angle theta where B = BH tan theta. The current is therefore proportional to tan theta, and the constant K = 2 r BH / (mu0 n) is the reduction factor of the instrument.
- Place the galvanometer on a firm bench away from magnets, steel objects and other current-carrying equipment.
- Level the base and turn the apparatus until the coil lies in the magnetic meridian, so the needle reads zero on the angular scale with no current flowing.
- Connect the coil in series with a battery, rheostat, ammeter and reversing key.
- Pass a steady current and note the deflection, then reverse the current and note it again; averaging the readings cancels small alignment errors.
- Repeat for several currents and tabulate I against tan theta.
A straight-line graph of I against tan theta verifies the tangent law, and its slope gives the reduction factor. When the coil constant is known, the same readings give the horizontal component of the Earth's magnetic field at the bench.
Key features
- Works on the tangent law, relating needle deflection to the ratio of two perpendicular magnetic fields.
- Compass needle with an angular scale placed at the centre of the coil, where the coil's field is used.
- Makes the magnetic field of a current-carrying circular coil measurable through needle deflection.
- Can be aligned with the magnetic meridian on the bench before readings are taken.
- Suited to student measurements of current, reduction factor and the horizontal component of the Earth's field.
Documentation and supply
Installation instructions and a manual are supplied with the apparatus. Most Lab Exports products carry a one-year manufacturer warranty.
Lab Exports manufactures the tangent galvanometer 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 Magnetism products
- Bar Magnet - Superior (SCL-M-11248)
- Horseshoe Magnet (SCL-M-11245)
- Electromagnet "U" Shape (SCL-M-11228)
- Electric Motor Model (SCL-M-11214)
- Demountable Transformer (SCL-M-11210)
- Induced Current Apparatus (SCL-M-11342)
The full range is in the Magnetism section of the Physics Lab range.
Frequently asked questions
What does a tangent galvanometer measure?
It measures current through the deflection of a compass needle: the current is proportional to the tangent of the deflection angle, with the reduction factor as the constant.
Why must the coil be set in the magnetic meridian?
The tangent law holds only when the coil's field is at right angles to the horizontal component of the Earth's field, which is the case when the plane of the coil lies along the magnetic meridian.
What is the price of the tangent galvanometer?
Prices are not published on the website. Add the tangent galvanometer to the Enquiry Cart with the Add To Cart button on this page, or email [email protected] with the house code SCL-M-11272 and the quantity, to receive a quotation.
Does Lab Exports manufacture the tangent galvanometer?
Yes. Lab Exports manufactures the tangent galvanometer at its works at 11/315, Lalita Park, Laxmi Nagar, Delhi 110092, under house code SCL-M-11272.
Request a quote
Email [email protected] with the house code SCL-M-11272 and the quantity, or add the tangent galvanometer to the Enquiry Cart with the Add To Cart button on this page. Tender buyers can also see the Tenders and OEM page.
