Thermal Expansion

IMPORTANT

Thermal Expansion: Overview

This Topic covers sub-topics such as Thermal Expansion, Time Period of Simple Pendulum, Anomalous Expansion of Water, Coefficients of Thermal Expansion, Thermal Stresses, Thermal Expansion in Liquids and, Thermal Expansion in Solids

Important Questions on Thermal Expansion

HARD
IMPORTANT

A steel metre scale is to be ruled so that the millimetre intervals are accurate to about 5×105 mm at a certain temperature. The maximum temperature variation allowed during ruling is (the co-efficient of linear expansion of steel =10×106 K1)

HARD
IMPORTANT

A metal rod is fixed rigidly at two ends so as to prevent its thermal expansion. If L, α and Y respectively denote the length of the rod, coefficient of linear thermal expansion and Young’s modulus of its material, then for an increase in temperature of the rod by T, the longitudinal stress developed in the rod is

EASY
IMPORTANT

If the volume of a block metal changes by 0.12%, when it is heated through 20 , then the coefficient of linear expansion is

MEDIUM
IMPORTANT

An iron plate is uniformly heated from 20°C to 80°C. The change in diameter of a circular hole of diameter 1m is x100cm. Find the value of xα=12×10-6/°C

EASY
IMPORTANT

The water pipes burst because the water inside them is expanding when it undergoes _____.

EASY
IMPORTANT

_____is an expansion when a solid is heated and there is a change in its volume.

HARD
IMPORTANT

An ideal gas is expanding such that pT2= constant. The coefficient of volume expansion of the gas is n T , then find n .

HARD
IMPORTANT

A hole is drilled in a copper sheet. The diameter of the hole is 4.24 cm at 27°C. What is the change in the diameter (in cm) of the hole when the sheet is heated to 227°C ? Coefficient of linear expansion of copper is 1.70×10-5 °C-1.

MEDIUM
IMPORTANT

A non-isotropic solid metal cube has coefficients of linear expansion as: 5× 10 5 / o C along the x-axis and 5× 10 6 / o C along the y and the z-axis. If the coefficient of volume expansion of the solid is C× 10 6 / o C then the value of C is _____________

HARD
IMPORTANT

A large steel wheel is to be fitted on a shaft of the same material. At 27oC, the outer diameter of the shaft is 8.70 cm and the diameter of the central hole in the wheel is 8.69 cm. The shaft is cooled using dry ice. At what temperature (in °C) (to the nearest integer) of the shaft does the wheel slip on the shaft? Assume the coefficient of linear expansion of the steel to be constant over the required temperature range.

[ α steel = 1 . 2 0 × 1 0 - 5 / K ]

EASY
IMPORTANT

Length of a wire at room temperature is 4.55 m. When the temperature increases upto 100 , then its length becomes 4.57 m. The coefficient of linear expansion (α) of the given wire is

MEDIUM
IMPORTANT

Ratio of linear, area and volume expansion in solids is

HARD
IMPORTANT

A steel wire of uniform cross-section of 1 mm2 is heated upto 50°C and clamped rigidly at its ends. If the temperature of wire falls to 40°C, change in tension in the wire is (coefficient of linear expansion of steel is 1.1×10-5 C-1o and Young's modulus of elasticity of steel is 2×1011 N m-2)

EASY
IMPORTANT

The graph shows the change in volume of water as its temperature is raised from 0°C. What is this behaviour of water called?
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EASY
IMPORTANT

A metal rod of Young's modulus Y and coefficient of thermal expansion α is held at its two ends such that its length remains invariant. If its temperature is raised by t°C, the linear stress developed in it, is

MEDIUM
IMPORTANT

A square plate has three circular holes of the same radius so that centre of each hole is equidistant from the centre of the square plate. A ABC can be formed by joining the centres of the holes as shown in the figure. The plate is placed on a frictionless horizontal surface. If we increase the temperature, then

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HARD
IMPORTANT

A metal rod of cross-sectional area 10-4 m2 is hanging in a chamber kept at 20°C with a weight attached to its free end. The coefficient of thermal expansion of the rod is 2.5×10-6 K-1 and its Young's modulus is 4×1012 N m-2. When the temperature of the chamber is lowered to T, then a weight of 5000 N needs to be attached to the rod, so that its length is unchanged. Then, T is

MEDIUM
IMPORTANT

When temperature of water is reduced below _____, it expands.

EASY
IMPORTANT

Observe the given graph and choose the name of the process represented in the figure.

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EASY
IMPORTANT

A steel rod, clamped at its two ends, rests on a fixed horizontal base. The rod is unstrained at 20 °C. The absolute value of the longitudinal strain developed in the rod if the temperature rises to 60 °C is.

(coefficient linear expansion of steel =1.2×105/ °C)