Thermal Properties Of Matter (SAQs)

Physics-1 | 12. Thermal Properties of Matter – SAQs:
Welcome to SAQs in Chapter 12: Thermal Properties of Matter. This page covers the most important FAQs for Short Answer Questions. Each answer is provided in simple English, with a Telugu explanation, and formatted according to the exam style. This helps in understanding the material and achieving top marks in your final exams.

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SAQ-1 : In what way is the anomalous behavior of water advantages to aquatic animals?

Introduction

Water is known for its unique properties that deviate from typical liquid behavior, often referred to as the “anomalous behavior of water.” These anomalies, such as a higher boiling point, maximum density at 4°C, and large specific heat capacity, are crucial for supporting life in aquatic environments.

Advantages of Water’s Anomalous Behavior to Aquatic Animals

1. High Specific Heat Capacity:
   • Water’s high specific heat capacity allows it to absorb and store a large amount of heat energy without significantly rising in temperature.
   • This property aids in maintaining a stable water temperature, providing a consistent and favorable living environment for aquatic animals.
2. High Heat of Vaporization:
   • The high heat of vaporization of water means it requires a lot of heat energy to transition from liquid to gas.
   • This trait is beneficial for aquatic animals in warmer regions, as evaporating water from their bodies or surroundings absorbs heat, helping to cool them down and prevent overheating.
3. Density Anomaly:
   • Water reaches its maximum density at 4°C and expands as it cools below this temperature, a behavior opposite to most substances.
   • The formation of less dense ice on the surface of water bodies during cold weather acts as an insulator, protecting aquatic life below from extreme cold.
4. Solvent Properties:
   • Known as the “universal solvent,” water’s ability to dissolve various substances, including salts, minerals, gases, and nutrients, is vital for aquatic animals.
   • These creatures benefit from easy access to essential nutrients and can eliminate waste products efficiently, thanks to water’s excellent solvent properties.
5. Surface Tension: Water’s high surface tension supports certain aquatic animals and plants, enabling behaviors such as walking on the water’s surface or creating floating structures.

Summary

The anomalous behavior of water, including its high specific heat capacity, heat of vaporization, density anomaly, solvent properties, and surface tension, offers numerous advantages to aquatic animals. These properties contribute to stable temperatures, protection against temperature extremes, nutrient accessibility, waste disposal, and unique behaviors in aquatic ecosystems. Water’s unique characteristics are essential for the survival and prosperity of aquatic life.

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SAQ-2 : Explain Conduction, Convection and Radiation with examples.

Introduction

Heat transfer is the process by which thermal energy is exchanged between objects or regions. There are three primary methods of heat transfer: conduction, convection, and radiation, each with distinct characteristics and applications in everyday life.

Conduction

1. Conduction is the heat transfer within a solid material or between touching objects through molecular collisions, occurring due to a temperature difference.
2. Examples of Conduction:
   • Touching a Hot Pan: Heat is conducted from the hot pan to your hand, demonstrating heat transfer through direct contact.
   • Heating a Spoon in Hot Liquid: A metal spoon in hot liquid becomes warm through conduction, where heat from the liquid transfers to the spoon.

Convection

1. Convection is the transfer of heat through the movement of fluids (liquids or gases), driven by differences in temperature and density.
2. Examples of Convection:
   • Boiling Water: In a boiling pot of water, a convection current circulates water, evenly distributing heat.
   • Sea Breeze: Land heats up faster than the ocean, causing warm air over land to rise and cooler ocean air to replace it, forming a sea breeze.

Radiation

1. Radiation is the transfer of heat in the form of electromagnetic waves, such as infrared radiation, and does not require a medium or direct contact between objects.
2. Examples of Radiation:
   • Sunlight: The Sun’s energy reaches the Earth through radiation, warming its surface and providing light.
   • Heating with an Infrared Heater: Infrared heaters emit radiation that heats objects and people in a room without needing direct contact.

Summary

Conduction involves heat transfer within solids or between objects in contact, convection involves the movement of fluids due to temperature and density differences, and radiation is the transfer of heat through electromagnetic waves without a medium. These mechanisms are essential in various processes and phenomena in our daily lives and the natural world.

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SAQ-3 : Pendulum clocks generally go fast in winter and slow in summer. Why?

Introduction

The functioning of pendulum clocks is known to vary with seasons, typically going fast in winter and slowing down in summer. This phenomenon is primarily due to changes in temperature and its impact on the pendulum’s length.

Reasons for Seasonal Variations

1. Thermal Expansion and Contraction:
   • The primary reason behind this seasonal variation is the thermal expansion and contraction of the pendulum rod.
   • Metal, a common material for pendulum rods, expands when heated and contracts when cooled.
2. Length of the Pendulum and Time Period:
   • The time period of a pendulum clock is directly related to its length, governed by the formula $$T = 2\pi \sqrt{\frac{L}{g}}$$ where T is the time period, L is the length of the pendulum, and g is the acceleration due to gravity.
   • In winter, the cooler temperatures cause the pendulum rod to contract, slightly shortening its length. A shorter pendulum has a shorter period, leading the clock to go fast.
   • Conversely, in summer, the higher temperatures cause the pendulum rod to expand, increasing its length. A longer pendulum has a longer period, causing the clock to slow down.

Summary

Pendulum clocks are affected by seasonal temperature changes due to the thermal expansion and contraction of the pendulum rod. This change in length alters the pendulum’s time period, making the clock run faster in colder temperatures (winter) and slower in warmer temperatures (summer). Understanding this phenomenon is crucial for maintaining the accuracy of pendulum clocks and highlights the impact of environmental conditions on mechanical devices.