CSLB Class B General Contractor's License Practice Exam

What is the amount of effort needed to raise the temperature of one pound of water by one degree Fahrenheit called?

1. Watt

2. British Thermal Unit (BTU)

3. Calorie

4. Joule

The correct answer is: British Thermal Unit (BTU)

The amount of effort needed to raise the temperature of one pound of water by one degree Fahrenheit is known as a British Thermal Unit, or BTU. This unit is specifically designed to quantify the amount of heat energy required for this precise change in temperature for water, which is a standard reference substance in thermal calculations. BTUs are commonly used in the heating and air conditioning industries to describe the power of heaters and air conditioners. A BTU can be visualized in practical terms, such as how much energy is needed to heat food or how energy consumption is measured for heating systems. Its relation to the weight of water emphasizes the unit’s relevance in everyday situations, such as cooking or environmental control in buildings. In contrast, a Watt is a measure of power, defining energy transfer per unit of time rather than a single thermal unit. A Calorie is defined in relation to the heating of water as well but specifies the heat needed to raise one gram of water by one degree Celsius, which differs from the larger gallon measurement in the BTU. Joules are another unit of energy in the International System of Units, but they do not specifically relate to the thermal properties of water as the BTU does. Therefore, understanding these distinctions clarifies why the British Thermal