EASY
Physics
IMPORTANT
Earn 100

A pendulum clock loses 12 s a day if the temperature is 40°C and goes fast by 4 s a day if the temperature is 20°C. Find the temperature at which the clock will show correct time and the coefficient of linear expansion of the metal of the pendulum shaft.

Important Questions on Thermometry, Thermal Expansion and Calorimetry

HARD
Physics
IMPORTANT

A brass wire 1.8 m long at 27 °C is held taut with little tension between two rigid supports. If the wire is cooled to a temperature of -39 °C, what is the tension developed in the wire, if its diameter is 2.0 mm? Co-efficient of linear expansion of brass is 2.0×10-5 K-1; Young’s modulus of brass is 0.91×10 Pa.

MEDIUM
Physics
IMPORTANT

A rod has length 2 m at a temperature of 20°C. Find the free expansion of the rod, if the temperature is increased to 50°C, then find stress produced when the rod is fully prevented to expand. Y=2×1011 Nm-2; α=15×10-6/C

EASY
Physics
IMPORTANT

A rod has length 2 m at a temperature of 20°C. Find the free expansion of the rod, if the temperature is increased to 50°C, then find stress produced when the rod is permitted to expand by 0.4 mmY=2×1011 Nm-2; α=15×10-6/C

EASY
Physics
IMPORTANT

Two rods of different metals having the same area of cross section A are placed between the two massive walls as shown in the given figure. The first rod has a length l1, coefficient of linear expansion α1 and Young's modulus Y1. The corresponding quantities for second rod are l2,α2 and Y2. The temperature of both the rods is now raised by t°C.

Question Image

(a) Find the force with which the rods act on each other (at higher temperature) in terms of given quantities.

(b) Also find the length of the rods at higher temperature.

MEDIUM
Physics
IMPORTANT

A steel ball initially at a pressure 1.0×105 Pa is heated from 20°C to 120°C keeping its volume constant. Find the pressure inside the ball.

The coefficient of linear expansion of steel is 12×106°C1.

Bulk modulus of steel is 1.6×1011 N m2.

MEDIUM
Physics
IMPORTANT

A composite rod is made by joining a copper rod, end to end, with a second rod of different material but of the same area of cross section. At 25°C, the composite rod is 1 m long and the copper rod is 30 cm long. At 125°C the length of the composite rod increases by 1.91 mm. When the composite rod is prevented from expanding by holding it between two rigid walls, it is found that the constituent rods have remained unchanged in length in spite of rise of temperature. Find Young's modulus and the coefficient of linear expansion of the second rod (Y of copper =1.3×1010 N m-2 and α of copper =17×10-6 K-1 ).

EASY
Physics
IMPORTANT

At room temperature 25°C the length of a steel rod is measured using a brass centimetre scale. The measured length is 20 cm. If the scale is calibrated to read accurately at temperature 0°C, find the actual length of steel rod at room temperature.

HARD
Physics
IMPORTANT

A steel tape 1 m long is correctly calibrated for a temperature of 27.0 oC. The length of a steel rod measured by this tape is found to be 63.0 cm on a hot day when the temperature is 45.0 oC. What is the actual length of the steel rod on that day? What is the length of the same steel rod on a day when the temperature is 27.0 oC? Coefficient of linear expansion of steel =1.20×10-5 K-1.