EASY
Earn 100

Explain the term: breaking stress.

Important Questions on Elasticity

MEDIUM
Physics>Mechanics>Elasticity>Stress-Strain Curve
The bulk modulus of a spherical object is B. If it is subjected to uniform pressure p, the fractional decrease in radius is
MEDIUM
Physics>Mechanics>Elasticity>Stress-Strain Curve
A metal rod of length L and cross-sectional area A is heated through T °C. What is the force required to prevent the expansion of the rod lengthwise?
[Y = Young's modulus of the material of rod, α= coefficient of linear expansion]
MEDIUM
Physics>Mechanics>Elasticity>Stress-Strain Curve
A steel rail of length 5 m and area of cross section 40 cm2 is prevented from expanding along its length while the temperature rises by 10°C . If coefficient of linear expansion and Young's modulus of steel are 1.2×10-5  K-1 and 2×1011 N m-2 respectively, the force developed in the rail is approximately:
MEDIUM
Physics>Mechanics>Elasticity>Stress-Strain Curve
A solid sphere of radius r made of a soft material of bulk modulus K is surrounded by a liquid in a cylindrical container. A massless piston of area a floats on the surface of the liquid, covering entire cross-section of cylindrical container. When a mass m is placed on the surface of the piston to compress the liquid, the fractional decrement in the radius of the sphere drr , is:
HARD
Physics>Mechanics>Elasticity>Stress-Strain Curve
A steel wire is suspended vertically from a rigid support. When the wire is loaded with a weight in air, it is extended by xa. When the weight is completely inside the water, the extension becomes xw. The relative density of the material of the weight is,
EASY
Physics>Mechanics>Elasticity>Stress-Strain Curve
In materials like aluminium and copper,  the correct order of magnitude of various elastic modulii is :
EASY
Physics>Mechanics>Elasticity>Stress-Strain Curve
A rubber cord of density d, Young's modulus Y and length L is suspended vertically. If the cord extends by a length 0.5L under its own weight, then L is
MEDIUM
Physics>Mechanics>Elasticity>Stress-Strain Curve
A boy’s catapult is made of rubber cord which is 42 cm long, with 6 mm diameter of cross-section and of negligible mass. The boy keeps a stone weighing 0.02 kg on it and stretches the cord by 20 cm by applying a constant force. When released, the stone flies off with a velocity of 20 ms-1 . Neglect the change in the area of cross-section of the cord while stretched. The Young’s modulus of rubber is closest to:
MEDIUM
Physics>Mechanics>Elasticity>Stress-Strain Curve
A load of mass M kg is suspended from a steel wire of length 2 m and radius 1.0 mm in Searle's apparatus experiment. The increase in length produced in the wire is 4.0 mm. Now the load is fully immersed in a liquid of relative density 2. The relative density of the material of load is 8. The new value of increase in length of the steel wire is:
MEDIUM
Physics>Mechanics>Elasticity>Stress-Strain Curve
The Young's modulus of steel is twice that of brass. Two wires of same length and of same area of cross-section, one of steel and another of brass are suspended from the same roof. If we want the lower ends of the wires to be at the same level, then the weights added to the steel and brass wires must be in the ratio of:
HARD
Physics>Mechanics>Elasticity>Stress-Strain Curve
A thin 1 m long rod has a radius of 5 mm. A force of 50π×103 N is applied at one end to determine its Young's modulus. Assume that the force is exactly known. If the least count in the measurement of all lengths is 0.01 mm, which of the following statements is false?
EASY
Physics>Mechanics>Elasticity>Stress-Strain Curve
Breaking stress of a steel wire is p and the density of steel is ρ. The greatest length of steel wire that can hang vertically without breaking is
EASY
Physics>Mechanics>Elasticity>Stress-Strain Curve
When a block of mass M is suspended by a long wire of length L, the length of the wire becomes L+l. The elastic potential energy stored in the extended wire is
MEDIUM
Physics>Mechanics>Elasticity>Stress-Strain Curve
One end of a slack wire (Young's modulus, Y, length, L and cross-sectional area, A) is clamped to a rigid wall and the other end to a block (mass m) which rests on a smooth horizontal plane. The block is set in motion with a speed, v. What is the maximum distance the block will travel after the wire becomes taut?
MEDIUM
Physics>Mechanics>Elasticity>Stress-Strain Curve
Young's moduli of two wires A and B are in the ratio  7:4 . Wire A is 2 m long and has radius R. Wire B is 1.5 m long and has radius 2 mm. If the two wires stretch by the same length for a given load, the value of R is close to:
MEDIUM
Physics>Mechanics>Elasticity>Stress-Strain Curve
A wire of length L and area of cross section A is made of material of Young’s modulus Y. It is stretched by an amount x. The work done in stretching the wire is
EASY
Physics>Mechanics>Elasticity>Stress-Strain Curve
Copper of fixed volume V is drawn into wire of length l. When this wire is subjected to a constant force F, the extension produced in the wire is ∆l. Which of the following graph is a straight line?
HARD
Physics>Mechanics>Elasticity>Stress-Strain Curve
An external pressure P is applied on a cube at 0°C so that it is equally compressed from all sides. K is the bulk modulus of the material of the cube and α is its coefficient of linear expansion. Suppose we want to bring the cube to its original size by heating. The temperature should be raised by:
EASY
Physics>Mechanics>Elasticity>Stress-Strain Curve
A wire of diameter 1 mm breaks under a tension of 1000 N. Another wire of the same material as that of the first one, but of diameter 2 mm breaks under a tension of:
MEDIUM
Physics>Mechanics>Elasticity>Stress-Strain Curve
The elastic limit of brass is 379 MPa. The minimum diameter of a brass rod if it is to support a 400 N load without exceeding its elastic limit will be