Exams › JEE Main › Physics

The elastic limit of brass is 379 MPa. What is the minimum diameter of a brass rod that can support a 400 N load without exceeding its elastic limit?

1. 1.16 mm
2. 0.90 mm
3. 1.36 mm
4. 1.00 mm

Correct answer: 1.16 mm

Solution

The minimum area is 400/379e6 = 1.055e-6 m²; converting this circular area to a diameter gives about 1.16 mm.

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 →