Question

Read the assertion and reason carefully to mark the correct option out of the option given below. (a) If both assertion and reason are true and the reason is the correct explanation of the reason. (b) If both assertion and reason are true but reason is not the correct explanation of the assertion. (c) If assertion is true but reason is false. (d) If the assertion and reason both are false. (e) If assertion is false but reason is true. Assertion: Fahrenheit is the smallest unit measuring temperature. Reason: Fahrenheit was the first temperature scale used for measuring temperature. (A) \(a\) (B) b (C) \(c\) (D) d (E) e

Short answer

\( \boxed{ \text{E}} \)

Step-by-step solution

Evaluate the Assertion

Fahrenheit is a unit for measuring temperature, but it is not the smallest unit. Celsius, Kelvin, and Fahrenheit scales all have different increments per unit, and Celsius and Kelvin have the same increment size, which is smaller than Fahrenheit's increment size. Therefore, the assertion is false.

Evaluate the Reason

Fahrenheit was the first temperature scale used for measuring temperature. This statement is true, as the Fahrenheit scale was developed in 1724 by physicist Daniel Fahrenheit, which was the first widely used temperature scale.

Identify the Relationship between Assertion and Reason

Since the assertion is false and the reason is true, there is no need to check if the reason correctly explains the assertion.

Select the Correct Option

Based on our analysis, the assertion is false, and the reason is true. So, the correct option is: (E) e

Key concepts

Temperature Scales

Temperature scales are essential for measuring temperature, a basic concept in physics and everyday life. There are several commonly used temperature scales, each with its own unique characteristics:

• Celsius: Water freezes at 0°C and boils at 100°C under standard atmospheric conditions. This scale is widely used around the world, especially in scientific contexts.
• Fahrenheit: In this scale, water freezes at 32°F and boils at 212°F. It is primarily used in the United States for non-scientific applications.
• Kelvin: The Kelvin scale starts at absolute zero, the lowest possible temperature, 0 K. Water freezes at 273.15 K and boils at 373.15 K. It is often used in scientific research because it directly relates to the kinetic energy of particles.

Each scale has its own applications and is important for understanding different scientific phenomena. It's crucial to know how to convert between these scales to interpret data accurately.

Assertion Reason Questions

Assertion reason questions are a common format used in physics examinations. They assess a student's ability to understand the link between two statements: the assertion and the reason.

• Assertion: This is a statement that proposes a fact or a conclusion.
• Reason: This statement provides an explanation or justification for the assertion.

Students need to determine not only the truthfulness of each statement separately but also whether the reason appropriately explains the assertion. This evaluation helps develop critical thinking and understanding of logical relationships, which are essential skills in both physics and broader scientific fields.

Fahrenheit Scale

The Fahrenheit scale was the first widely used temperature scale, developed by Daniel Fahrenheit in 1724. It is characterized by its use of brine and pure water for calibration points, with the freezing point of water at 32°F and the boiling point at 212°F.

This scale was primarily used for its practical benefits in daily weather reporting and basic household purposes, especially in the United States. It divides the range between freezing and boiling points of water into 180 increments, which are larger than the Celsius and Kelvin increments.

• Despite its historical importance, the Fahrenheit scale is less commonly used in scientific studies.
• The larger degree size on this scale means that temperature changes can appear more substantial when measured in degrees Fahrenheit.

Understanding the Fahrenheit scale is key when interpreting temperatures in contexts where it is still prevalent.

Celsius and Kelvin Comparison

Celsius and Kelvin are two temperature scales frequently used in scientific contexts, and understanding their comparison is essential.

• The Celsius scale is based on water's freezing and boiling points, with a 100-degree difference, making it intuitive for practical everyday use.
• The Kelvin scale, starting from absolute zero, is aligned with the concept of absolute temperature, making it fundamental in thermodynamics.

The increments in Celsius and Kelvin are identical; an increase of 1 degree in Celsius is equivalent to an increase of 1 Kelvin.

When converting from Celsius to Kelvin, we simply add 273.15 to the Celsius temperature, reflecting their direct correlation. This straightforward relationship simplifies calculations in scientific applications where absolute temperature values are required.