Thermal Expansion

IMPORTANT

Thermal Expansion: Overview

This topic consists of various concepts like Thermal Expansion,Thermal Expansion in Solids,Linear Expansion in Solids, etc.

Important Questions on Thermal Expansion

EASY
IMPORTANT

A thin aluminium plate has an area 286 cm2 at 20 °C Find its area when it is heated to 180 °C (β for aluminium = 4.9×10-5 °C-1))

EASY
IMPORTANT

A brass rod and a lead rod each 80 cm long at 0°C are clamped together at one end with their free ends coinciding. The separation of free ends of the rods if the system is placed in a steam bath is (αbrass=18×10-6 °C-1, αlead=28×10-6 °C-1 )

EASY
IMPORTANT

Give an example of volume expansion of a liquid on heating. The area of a solid substance at a temperature of T1 K is A1 m2 and that at a temperature of T2 K isA2 m2 . Write down the mathematical expression for the coefficient of area expansion with unit, of that solid substance

EASY
IMPORTANT

 If the temperature of body is increased by 200°C then the percentage decrease in its density is [γ= (3.75 × 10-5)C]
 

MEDIUM
IMPORTANT

A pendulum clock keeps correct time at 0°C. Mean coefficient of linear expansion is α °C-1. If the temperature of the room rises by a small amount of t°C, then find the ratio of time period at t°C to 0°C

EASY
IMPORTANT

A thin metal wire of length l increases in length by 0.1% on heating it from temperature θ1, to θ2. If a plate of the same material is heated from θ1 to θ2, which has dimensions 2l×3l, then percentage increase in its area is

MEDIUM
IMPORTANT

The internal volume of a glass flask is V cm3, how much volume of mercury is kept in the flask so that the volume of the empty part of the flask remains the same at all elevations? (Volume expansion coefficient of mercury is 1.8×10-4 °C and linear expansion coefficient of glass =9×10-6 °C).

EASY
IMPORTANT

A long cylindrical vessel of volume V and coefficient of linear expansion α contains a liquid. The level of liquid has not changed on heating. The coefficient of real expansion of the liquid is

EASY
IMPORTANT

γA of liquid is 78 of γR of liquid. αg of vessel is

EASY
IMPORTANT

A hole of diameter 5 cm is drilled in a metal sheet at 30 °C. The linear expansion of metal is 2×10-5 K-1. The diameter of the hole when the temperature is raised to 230 °C, is equal to

EASY
IMPORTANT

Find the ratio of the length of a steel rod and a copper rod if the steel rod is 4 cm longer than the copper rod at any temperature.
[The coefficient of linear expansion for steel and copper are 1.1×10-5 C and 1.7×10-5 C respectively]

MEDIUM
IMPORTANT

Take two bottles of the same size. Tie a ballon to the mouth of each bottle, and place one bottle in a tub of hot water while the other bottle in the tub having ice. What will you observe after some time?

EASY
IMPORTANT

A metal tape is calibrated at 25°C. On a cold day when the temperature is -15°C, the percentage error in the measurement of length is
(Coefficient of linear expansion of metal =1×10-5C-1)

MEDIUM
IMPORTANT

A lamp post of negligible mass of length l and cross sectional area S=10 cm2 is made of material with linear expansion coefficient α=1.1×10-5 K-1 and Young 's modulus Y=2.0×1011 N m-2. If temperature of lamp post is raised by ΔT=10 K then a mass m×102kg should be put on the lamp post, so that there is no change in the length of lamp post, the value of m11 is ( take g=10 m s-2)

EASY
IMPORTANT

A metal bar is 2.4 m long. After heating, it's length increases by 2%. What is the new length?

EASY
IMPORTANT

The coefficient of cubical expansion of a solid is 27 × 10-6° C-1. If the temperature is measured on Fahrenheit scale, numerical value of coefficient of linear expansion of solid is

MEDIUM
IMPORTANT

A hollow metallic cube has edge length 12cm. A liquid whose coefficient of volume expansion is 6×10-10C-1 is poured into it upto height 3cm. When temperature increases, height of liquid in cube remains unchanged. Coefficient of linear expansion of cube's material is n×10-10C-1, find n.

EASY
IMPORTANT

A uniform copper rod of length 50 cm and diameter 3.0 mm is kept on a frictionless horizontal surface at 20°C. The coefficient of linear expansion of copper is 2.0×10-5 K-1 and Young's modulus is 1.2×1011 N m-2. The copper rod is heated to 100°C, then the tension developed in the copper rod is

HARD
IMPORTANT

Derive αv=1T. for an Ideal gas .

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