⚡ Thermal expansion is the expansion of a solid, liquid, or gas due to a change in temperature. 📏 There are three types of thermal expansion: linear, areal, and volume. 🌡 Upon heating, the distance between any two points on a solid increases. ⭕ When a metal sheet with two holes of unequal diameters is heated, both holes increase in diameter. 🔮 When a solid ball of metal with a concentric spherical cavity is heated, the volume and area of the cavity increase. 📏 In uniform rods, the change in length due to thermal expansion is directly proportional to its original length, the change in temperature, and the coefficient of linear expansion. 🧮 Equation for linear thermal expansion: ΔL = L_0 α ΔT 📏 Final length of a uniform rod after thermal expansion: L = L_0 + ΔL = L_0 + L_0 α ΔT 🧮 Coefficient of linear expansion (α): Units of K^-1 or °C^-1 ⏳ When a pendulum clock is heated, the time period increases and the clock loses time. ⚠ Thermal stress is the stress developed in a material due to a change in temperature. 📏 Thermal strain is the change in length per unit length of a material due to a change in temperature. ⚖ Force per unit area due to thermal stress is equal to the Young's modulus of the material multiplied by the thermal strain. ⚠ The stress developed in a rod when it is heated but prevented from expanding is independent of the length of the rod. ⚖ When two rods of different materials with different coefficients of thermal expansion and Young's moduli are fixed between two rigid massive walls and heated such that they undergo the same increase in temperature, the thermal stresses developed in the two rods will be equal if the ratio of the coefficients of thermal expansion is equal to the ratio of the Young's moduli.
thermal properties of matter. 🌡 1. **Temperature and Heat : - *Temperature* is a relative measure of hotness or coldness. It indicates how hot or cold an object is. For example, a hot utensil has a high temperature, while an ice cube has a low temperature. - *Heat* is the form of energy transferred between systems due to temperature differences. When an object is heated, its temperature may rise, it may expand, or change state. 2. **Measurement of Temperature : - We use **thermometers** to measure temperature. The SI unit of temperature is the **kelvin (K)**, and °C is commonly used. - Heat transfer occurs when the temperature of a body and its surroundings differ. Heat flows from hotter to colder regions. 3. **Key Thermal Properties : - *Specific Heat Capacity**: The heat needed to change the temperature of a substance. - *Thermal Conductivity**: Ability to conduct thermal energy. - *Thermal Expansion**: Change in size with temperature. - *Thermal Diffusivity**: Rate of conducting thermal energy. Remember, these properties play a crucial role in how materials respond to changes in temperature! 🌟
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⚡ Thermal expansion is the expansion of a solid, liquid, or gas due to a change in temperature.
📏 There are three types of thermal expansion: linear, areal, and volume.
🌡 Upon heating, the distance between any two points on a solid increases.
⭕ When a metal sheet with two holes of unequal diameters is heated, both holes increase in diameter.
🔮 When a solid ball of metal with a concentric spherical cavity is heated, the volume and area of the cavity increase.
📏 In uniform rods, the change in length due to thermal expansion is directly proportional to its original length, the change in temperature, and the coefficient of linear expansion.
🧮 Equation for linear thermal expansion: ΔL = L_0 α ΔT
📏 Final length of a uniform rod after thermal expansion: L = L_0 + ΔL = L_0 + L_0 α ΔT
🧮 Coefficient of linear expansion (α): Units of K^-1 or °C^-1
⏳ When a pendulum clock is heated, the time period increases and the clock loses time.
⚠ Thermal stress is the stress developed in a material due to a change in temperature.
📏 Thermal strain is the change in length per unit length of a material due to a change in temperature.
⚖ Force per unit area due to thermal stress is equal to the Young's modulus of the material multiplied by the thermal strain.
⚠ The stress developed in a rod when it is heated but prevented from expanding is independent of the length of the rod.
⚖ When two rods of different materials with different coefficients of thermal expansion and Young's moduli are fixed between two rigid massive walls and heated such that they undergo the same increase in temperature, the thermal stresses developed in the two rods will be equal if the ratio of the coefficients of thermal expansion is equal to the ratio of the Young's moduli.
thermal properties of matter. 🌡
1. **Temperature and Heat :
- *Temperature* is a relative measure of hotness or coldness. It indicates how hot or cold an object is. For example, a hot utensil has a high temperature, while an ice cube has a low temperature.
- *Heat* is the form of energy transferred between systems due to temperature differences. When an object is heated, its temperature may rise, it may expand, or change state.
2. **Measurement of Temperature :
- We use **thermometers** to measure temperature. The SI unit of temperature is the **kelvin (K)**, and °C is commonly used.
- Heat transfer occurs when the temperature of a body and its surroundings differ. Heat flows from hotter to colder regions.
3. **Key Thermal Properties :
- *Specific Heat Capacity**: The heat needed to change the temperature of a substance.
- *Thermal Conductivity**: Ability to conduct thermal energy.
- *Thermal Expansion**: Change in size with temperature.
- *Thermal Diffusivity**: Rate of conducting thermal energy.
Remember, these properties play a crucial role in how materials respond to changes in temperature! 🌟
Sir you are explaining very nice but please upload oscillation chapter also sir
Excellent
Same to same alakh sir questions only same questions slide 😅
Sir please upload oscilation chapter
99 mm rod
6.8 cm
1.7 not 17
Doubt....Why 17why not 1.7 please tell me