Find the length of an iron rod at 110°C if at 10°C, the length of the rod is 20 cm. [Volume expansion coefficient of iron = 36 × 10⁻⁶ /°C]
WBBSE
Class X
Physical Science
Thermal phenomena
03 Mark
2025
Initial length (L₁) = 20 cm
Initial temperature = 10°C
Final temperature = 110°C
Rise in temperature (ΔT) = 110 − 10 = 100°C
Volume expansion coefficient (γ) = 36 × 10⁻⁶ /°C
Linear expansion coefficient (α) = \frac{\gamma}{3}
= \frac{36 \times 10^{-6}}{3}
= 12 × 10⁻⁶ /°C
Using the formula, L₂ = L₁ (1 + αΔT)
L₂ = 20 (1 + 12 × 10⁻⁶ × 100)
L₂ = 20 (1 + 0.0012)
L₂ = 20 × 1.0012
L₂ = 20.024 cm
Hence, the length of the iron rod at 110°C is 20.024 cm.
Related Questions
More WBBSE Moderate level questions
1/12
Q.
Define Thermal conductivity. What is the SI unit of Thermal resistance?
A.
Thermal Conductivity is the ability of a material to conduct heat. It...
Q.
Define the coefficient of volume expansion of a solid and write its mathematical form.
A.
Definition: The coefficient of volume expansion of a solid is defined as...
Q.
The coefficient of thermal conduction depends on
A.
(b) Property of the material of the conductor Explanation The coefficient of...
Q.
Define the coefficient of apparent expansion and the coefficient of real expansion of a liquid....
A.
Coefficient of apparent expansion: The apparent increase in volume per unit original...
Q.
Explain the statement: “The coefficient of linear expansion of iron is 12 × 10⁻⁶ /°C”....
A.
The coefficient of linear expansion of iron is 12 × 10⁻⁶ /°C...
Q.
How many types of thermal expansion coefficients are there for a liquid?
A.
(c) 2 Explanation: For liquids, two types of thermal expansion coefficients are...
Q.
Why are there gaps at regular intervals between consecutive rails in a railway track? State...
A.
Gaps are left between railway rails to provide space for thermal expansion...
Q.
If coefficient of linear expansion of iron is 1.2 × 10⁻⁵ /°C, then coefficient of...
A.
True Explanation The relationship between the coefficients of expansion for an isotropic...
Q.
Write whether the following statement is True or False: Which physical quantity has the unit...
A.
Coefficient of Thermal Conductivity (Thermal Conductivity)
Q.
The value of coefficient of linear expansion of solid is the same in celsius scale...
A.
True. OR Diamond > Silver > Iron.
Q.
What is the unit of conductivity?
A.
a. mho·meter⁻¹
Q.
If the length and cross-sectional area of a conductor remain unchanged, what is the relationship...
A.
Thermal resistance, Rt = Since the length L and cross-sectional area A...