2024-03-29 郭梁浅 精彩小资讯
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NCERT Solutions for Class 11 Physics Chapter 11: Thermal Properties of Matter
Exercise 11.1
1. The temperature of a body is 25°C. What is its temperature on the Fahrenheit scale?
SOLUTION:
T(°F) = (9/5) T(°C) + 32
= (9/5) (25) + 32
= 77°F
2. A clinical thermometer has a range of 35°C to 42°C. What is the range of this thermometer on the Fahrenheit scale?
SOLUTION:
T(°F) = (9/5) T(°C) + 32
For 35°C, T(°F) = (9/5) (35) + 32 = 95°F
For 42°C, T(°F) = (9/5) (42) + 32 = 107.6°F
Therefore, the range of the thermometer on the Fahrenheit scale is 95°F to 107.6°F.
3. A thermometer has a linear scale with 50 equal divisions between the freezing point of water and the boiling point of water. What is the value of one scale division in terms of Celsius degrees?
SOLUTION:
One scale division = (100°C 0°C) / 50
= 2°C
Exercise 11.2
1. What is the S.I. unit of heat capacity?
SOLUTION:
The S.I. unit of heat capacity is joule per kelvin (J/K).
2. The heat capacity of water is 4.2 J/g°C. What does this mean?
SOLUTION:
This means that 1 gram of water requires 4.2 joules of heat energy to raise its temperature by 1°C.
3. A piece of metal of mass 100 g has a specific heat capacity of 0.1 J/g°C. How much heat energy is required to raise its temperature from 20°C to 50°C?
SOLUTION:
Heat energy required = mass × specific heat capacity × change in temperature
= 100 g × 0.1 J/g°C × (50°C 20°C)
= 300 J
Exercise 11.3
1. What are the three modes of heat transfer?
SOLUTION:
The three modes of heat transfer are:
Conduction
Convection
Radiation
2. Explain the process of conduction.
SOLUTION:
Conduction is the transfer of heat through direct contact between two objects. Heat flows from the hotter object to the colder object through the contact surface.
3. Give an example of convection.
SOLUTION:
An example of convection is the heating of water in a kettle. As the water at the bottom of the kettle is heated, it expands and becomes less dense. This less dense water rises to the top, while the cooler water from the top sinks to the bottom. This creates a convection current, which distributes heat throughout the water.
Exercise 11.4
1.
2.
3.
八字口砌石平面图绘制步骤：
材料：
图纸纸
尺子
圆规
铅笔
橡皮
步骤：
1. 确定图形尺寸：确定八字口的整体尺寸，包括宽度和长度。例如，如果八字口宽度为 6 米，长度为 8 米，则绘制一个矩形框，长 8 米，宽 6 米。
2. 绘制中线：在矩形框中间绘制一条垂直线和一条水平线，将矩形分为四等分。
3. 绘制斜线：从矩形框的四个角沿着中线延长两条对角线，形成一个“X”形。
4. 确定砌石宽度：确定砌石的宽度，例如 0.5 米。
5. 绘制砌石：沿着四个斜线画出等距的竖线，间隔距离等于砌石宽度。例如，如果砌石宽度为 0.5 米，则每条斜线上每间隔 0.5 米画一条竖线。
6. 绘制砌石弧形：在矩形框的四个角处，用圆规画出圆弧，半径等于砌石宽度的一半。例如，如果砌石宽度为 0.5 米，则圆弧半径为 0.25 米。
7. 绘制砌石顶面：沿着砌石的竖线画出水平线，表示砌石的顶部。
8. 绘制砌石端面：沿着矩形框的边沿画出水平线，表示砌石的端面。
提示：
使用尺子和铅笔确保线条直且准确。
使用橡皮擦除辅助线和错误。
在图纸上标注尺寸和注释，以便清楚理解。
根据需要可以添加其他详细信息，例如排水孔或接缝。
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