Mechanical Prop...

Two similar wires under the same load yield elongation of 0.1 mm and 0.05 mm respectively. If the area of cross-section of the first wire is 4 mm², then the area of cross-section of the second wire is

An iron rod of length 2m and cross section area of 50 mm², stretched by 0.5 mm, when a mass of 250 kg is hung from its lower end. Young\'s modulus of the iron rod is

A steel wire of 1 m long and 1 mm² cross-section area is hung from rigid end. When weight of 1 kg is hung from it then change in length will be (given Y = 2 × 10¹¹ N/m²)

To break a wire, a force of 10⁶ N/m² is required. If the density of the material is 3 × 10³ kg/m³, then the length of the wire which will break by its own weight will be

The extension in a string obeying Hooke\'s law is x. The speed of sound in the stretched string is v. If the extension in the string is increased to 1.5 x, the speed of sound will be

One end of uniform wire of length L and of weight W is attached rigidly to a point in the roof and a weight W₁ is suspended from its lower end. If S is the area of cross-section of the wire, the stress in the wire at a height 3L/4 from its lower end is

When a spring is stretched by a distance x, it exerts a force, given by F = (–5x – 16x³) N. The work done, when the spring is stretched from 0.1 m to 0.2 m is

A metalic rod of length l and cross-sectional area A is made of a material of Young modulus Y. If the rod is elongated by an amount y, then the work done is proportional to

Wires A and B are made from the same material. A has twice the diameter and three times the length of B. If the elastic limits are not reached, when each is stretched by the same tension, the ratio of energy stored in A to that in B is

A brass rod of cross-sectional area 1 cm² and length 0.2 m is compressed lengthwise by a weight of 5 kg. If Young\'s modulus of elasticity of brass is 1 × 10¹¹ N/m² and g = 10 m/sec², then increase in the energy of the rod will be