Mechanical Properties of Solids quiz

The SI unit of Young's modulus is:

Strain has:

The Young's modulus of a perfectly rigid body is:

Which state of matter has the smallest bulk modulus?

A change in shape without a change in volume is described by the:

Hooke's law holds in the:

For the same force and the same wire area, doubling the length makes the extension:

Compressibility is the:

An example of an elastomer is:

The maximum stress a material can bear before breaking is its:

Explain why mountains on Earth cannot be much higher than about 10 km. (2 marks)

Distinguish between tensile stress and shearing stress. (2 marks)

What is the elastic limit of a material? (2 marks)

What is meant by a ductile material and a brittle material? (2 marks)

Find the strain in a 4 m wire that extends by 2 mm. (2 marks)

Why are crane ropes made of many thin wires twisted together instead of one thick wire? (2 marks)

What is hydraulic stress? (2 marks)

Why does a beam bend less when its depth is increased? (2 marks)

Explain the term permanent set. (2 marks)

Which is more compressible, water or air? Give a reason. (2 marks)

A steel sphere is lowered to a depth in the ocean where the pressure is 10^7 Pa. Find its fractional change in volume. Take the bulk modulus of steel as 1.6 x 10^11 Pa. (3 marks)

A copper wire of length 2.2 m and a steel wire of length 1.6 m, both of diameter 3 mm, are joined end to end. A load stretches the combination by 0.7 mm. Find the ratio of the extensions of the copper and steel wires, taking Y for copper as 1.1 x 10^11 Pa and for steel as 2 x 10^11 Pa. (3 marks)

A rod of cross-section 10^-4 m^2 carries a load of 2000 kg. Find the stress in it. (3 marks)

Estimate the maximum height of a mountain if the rock has density 3 x 10^3 kg/m^3 and an elastic limit of 3 x 10^8 Pa. (3 marks)

A wire of length 1 m and area 10^-6 m^2 extends by 0.5 mm under a load of 10 kg. Find its Young's modulus. (3 marks)

Read the passage and answer the questions. A crane at a construction site lifts loads of up to 10^4 kg with a steel rope. The yield strength of steel is 3 x 10^8 Pa. (i) Find the weight of the maximum load. (ii) Find the minimum area of the rope. (iii) Why is a safety factor used in practice? (5 marks)

Read the passage and answer the questions. A submarine dives to a depth where the water pressure is 10^7 Pa. A steel sphere on it has bulk modulus 1.6 x 10^11 Pa. (i) Define the bulk modulus. (ii) Find the fractional change in the volume of the sphere. (iii) Would a rubber ball compress more or less? Why? (5 marks)

Read the passage and answer the questions. A student hangs weights on a long steel wire and measures the extension, keeping the load small. (i) Which law is verified? (ii) What shape is the load-extension graph? (iii) What happens if the load is increased beyond the elastic limit? (5 marks)

Read the passage and answer the questions. An engineer designs a beam for a bridge. The sag of a beam is proportional to W l^3/(b d^3 Y), where b is breadth and d is depth. (i) Which change reduces sag the most? (ii) Why is a very deep but narrow beam not used? (iii) Why are I-shaped sections used? (5 marks)

Read the passage and answer the questions. A rubber band and a steel spring are stretched by small amounts. (i) Which has the larger Young's modulus? (ii) Which is more elastic in the physics sense? (iii) Give one use of the elastic property of steel. (5 marks)

Explain the elastic behaviour of solids using the interatomic force model. (6 marks)

Describe the stress-strain curve of a metal wire and explain the different regions. (6 marks)

Define the three moduli of elasticity and compare their values for solids, liquids and gases. (6 marks)

Describe an experiment to determine the Young's modulus of a material of a wire. (6 marks)

Explain the applications of elastic behaviour in the design of crane ropes, beams and bridges, and in limiting the height of mountains. (6 marks)