Thermal Expansion of Solids, Liquids and Gases

IMPORTANT

Thermal Expansion of Solids, Liquids and Gases: Overview

This topic covers concepts, such as, Thermal Expansion, Thermal Expansion in Solids, Coefficient of Real Expansion & Relation for Volume Expansion etc.

Important Questions on Thermal Expansion of Solids, Liquids and Gases

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IMPORTANT

An aluminium cube of side 20 cm floats on mercury. The temperature of the system increases from 300 K to 350 K. Given that the density of aluminium and mercury at 300 K are 2.7 g c.c-1 and 13.6 g c.c-1. while the coefficient of volume expansion of mercury and linear expansion of aluminium are 1.8×10-4/°C and 23×10-6/°C respectively

MEDIUM
IMPORTANT

An experiment is performed to measure the coefficient of linear expansion of glass.
Experiment: A glass cylinder is filled completely by 100gm of mercury at temperature 0°C. When the temperature of the cylinder is increased upto θ=20°C, now it is observed that the cylinder can contain 99.7gm of mercury. In both the cases the temperature of the mercury is assumed to be equal to that of the cylinder. It is known that coefficient of volume expansion of mercury is γm=18×10-5C. The coefficient of linear expansion of glass measured from the experiment is α×10-5C..

Find the value of α

HARD
IMPORTANT

A block is hung by means of two identical wires having cross section area A1 mm2 as shown in the diagram. If temperature is lowered by ΔT10°C, find the mass (in kg ) to be added to hanging mass such that junction remains at initial position. Given that co-efficient of linear expansion α=2×10-5C and Young's modulus Y=5×1011 N m-2 for the wire.

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HARD
IMPORTANT

A wire is made by attaching two segments together end to end. One segment is made of aluminium and the other is steel. The effective coefficient of linear expansion of the two segment wire is 19×10-6 °C-1. The fraction length of aluminium is x11 then find x. (linear coefficients of thermal expansion of aluminium and steel are 23×10-6 °C-1 and 12×10-6 °C-1 respectively)

HARD
IMPORTANT

Strips of steel and brass are fused together as shown in the figure 1 below shown at room temperature. Which of the changes below causes this fused object to attain the shape shown in the figure 2? (Physical properties of steel and brass are given in the table)

 Physical Property  Steel  Brass  Density kg m-37.9×1038.9×103 Coefficient of expansion /C11×10-619×10-6 Bulk modulus Pa16×10106.1×1010 Tensile strength N m-25.0×1082.0×108 Compressive strength N m-25.0×1085.0×108

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MEDIUM
IMPORTANT

A vessel is partly filled with a liquid. Coefficient of cubical expansion of material of the vessel and liquid are γv and γ1 respectively. If the system is heated then volume unoccupied by the liquid will necessarily

MEDIUM
IMPORTANT

A simple seconds pendulum is constructed out of a very thin string of thermal coefficient of linear expansion α=20×10-4 °C-1 and a heavy particle attached to one end. The free end of the string is suspended from the ceiling of an elevator at rest. The pendulum keeps the correct time at 0 °C. When the temperature rises to 50 °C, the elevator operator of mass 60 kg being a student of physics accelerates the elevator vertically, to have the pendulum's correct time. Find the apparent weight (kg wt) of the operator when the pendulum keeps the correct time at 50 °CTake g=10 m s-2

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

In which of the following pairs of temperature scales, the size of the degree is identical?

EASY
IMPORTANT

Most matter contracts on heating and expands on cooling (Yes\No).

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

EASY
IMPORTANT

Exceptional expansion of water happens below _____ °C.

EASY
IMPORTANT

Ice is a _____ conductor of heat.

(Choose from the following: good/poor)

HARD
IMPORTANT

A planar frame is made of thin uniform rods. The length of section AB and EF is l1 and its coefficient of linear expansion is α1. The length of section CD is l2 and its coefficient of linear expansion is α2. CB and DE are of the same length having coefficient of linear expansion α2. Points A,B,E and F reside on same line, that is, sections AB and EF overlap. Then the ratio l1l2 for which the distance between end A and end F remains the same at all temperatures is α2nα1 then find the value of n.


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MEDIUM
IMPORTANT

A liquid having coefficient of volume expansion y0 is filled in a cylindrical glass vessel. Glass has a coefficient of linear expansion of αg. The liquid along with the container is heated to raise their temperature by ΔT. Mass of the container is negligible.

HARD
IMPORTANT

A glass flask of volume one litre at 0°C is filled fully with mercury. The flask and mercury are now heated to 100°C. How much mercury will spill out ( in cc) , if the coefficient of volume expansion of mercury is 1.82×10-4 C and linear expansion of glass is 0.1×10-4 C-1 respectively?

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.