Exams › JEE Main › Physics

A rigid square frame ABCD has four edge bars (AB, BC, CD, DA) and two diagonal bars (AC, BD) that merely touch freely at the centre. All joints are hinged. By an external arrangement, the bar AB is held in tension T at its ends, and the configuration is symmetric. Which statement is correct?

1. AD and BC are also under tension.
2. AD and BC are under compression.
3. AC and BD are under tension.
4. CD is under compression.

Correct answer: CD is under compression.

Solution

With AB pulled in tension, equilibrium at the joints requires the diagonals to push outward and the far edge CD to be compressed, so CD is under compression.

Related JEE Main Physics questions

• Select the incorrect statement.
• A steel wire has length l and cross-sectional area A. When a certain load is applied, it elongates by 1 cm. If the same load is now applied to another steel wire made of the same material, having twice the length and half the cross-sectional area, what will be its extension?
• For common metals such as aluminium and copper, which sequence correctly represents the relative magnitudes of the elastic moduli?
• A steel sheet fails under a shear stress of 3.5 × 10⁸ N m⁻². The approximate force required to punch a circular hole of diameter 1 cm through a steel plate 0.3 cm thick is:
• A copper wire of fixed volume V is stretched out to a length l. If a constant force F is applied to this wire and it elongates by Δl, which of the following plots would be a straight line?
• A material has Poisson’s ratio equal to 0.5. When a tensile force is applied to a wire made of this material, its cross-sectional area decreases by 4%. The corresponding percentage increase in its length is:

⚔️ Practice JEE Main Physics free + battle 1v1 →