Rigidity Apparatus (Searle's Pattern)

Product Code : EL-EAST-10414

Specifications

How the Searle's method experiment is done

The test wire is screwed to the mid-points of the two brass rods, and the rods hang horizontally from their hooks with the wire between them. Two kinds of oscillation are timed. When the free ends of the rods are drawn together and released, the rods swing in a horizontal plane and bend the wire; the period T1 of this motion gives Young's modulus, Y = 8 pi I L/(r^4 T1^2).

For the second part one rod is clamped rigidly so the wire hangs vertically with the other rod at its lower end. That rod twists the wire as it swings, acting as a torsion pendulum with period T2, which gives the modulus of rigidity, n = 8 pi I L/(r^4 T2^2). Here I is the moment of inertia of a rod about the wire, L the wire length and r its radius. The two periods together also give Poisson's ratio, sigma = T2^2/(2 T1^2) - 1.

1. Measure the length L of the test wire between the screws and its radius r with a screw gauge.
2. Weigh one brass rod and measure its length b to find its moment of inertia, I = M b^2/12.
3. Hang the rods from the hooks, draw their free ends together through a small distance, release and time 20 oscillations to get T1.
4. Clamp one rod so the wire hangs vertically with the other rod below, twist the lower rod slightly and time 20 torsional oscillations to get T2.
5. Calculate Y and n, then repeat with the other test wires supplied.

Key features

• Measures both modulus of rigidity and Young's modulus with one set-up
• Two brass rods of about 30 cm hang from hooks for free horizontal oscillation
• Three test wires with connecting screws supplied for comparison across samples
• Connecting screws fix the wire firmly at the mid-point of each rod
• Dynamical method variant with graduated iron rod also available

Documentation and supply

Most Lab Exports products carry a one-year manufacturer warranty.

Lab Exports manufactures the Searle's rigidity 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 Elasticity and Surface Tension products

• Hooke's Law Apparatus (EL-EAST-10413)
• Poisson's Ratio of Rubber Apparatus (EL-EAST-10415)
• Young's Modulus Apparatus (Vernier Type) (EL-EAST-10412)
• Capillary Tube Clamp (EL-EAST-10416)
• Young's Modulus Apparatus (Searle's Pattern) (EL-EAST-10411)
• Rising Table with Capillary Tube Clamp (EL-EAST-10417)

The full range is in the Elasticity and Surface Tension section of the Physics Lab range.

Frequently asked questions

What does the Searle's rigidity apparatus measure?

It measures the modulus of rigidity and the Young's modulus of wire materials by Searle's method, and the two results together give Poisson's ratio.

How many test wires are supplied?

Three test wires with connecting screws are supplied with the apparatus.

Is a dynamical method version available?

Yes. A variant uses a 16 x 1 inch graduated iron rod, marked 15-0-15 cm, with a thumb-screw weight.

What is the price of the Searle's rigidity apparatus?

Prices are not published on the website. Add the Searle's rigidity apparatus to the Enquiry Cart with the Add To Cart button on this page, or email [email protected] with the house code EL-EAST-10414 and the quantity, to receive a quotation.

Does Lab Exports manufacture the Searle's rigidity apparatus?

Yes. Lab Exports manufactures the Searle's rigidity apparatus at its works at 11/315, Lalita Park, Laxmi Nagar, Delhi 110092, under house code EL-EAST-10414.

Request a quote

Email [email protected] with the house code EL-EAST-10414 and the quantity, or add the Searle's rigidity apparatus to the Enquiry Cart with the Add To Cart button on this page. Tender buyers can also see the Tenders and OEM page.