Understanding the Analogy: Quantity and Unit

The question asks us to find a relationship between two words in the first pair, 'Light : Lumen', and then identify which of the options shares the same relationship. The first pair 'Light : Lumen' represents a physical quantity and its standard unit of measurement.

Specifically, Lumen is the SI derived unit of luminous flux, which is a measure related to how much 'light' is emitted or received. So, the relationship is Quantity : Unit of Measurement.

Now, let's examine each option to see which pair follows this Quantity : Unit relationship:

• Option 1: Temperature : Candela

  Temperature is a physical quantity that measures the degree of hotness or coldness. The standard unit for temperature in the SI system is Kelvin (K). Candela (cd) is the SI base unit of luminous intensity, which is a measure of the power emitted by a light source in a particular direction. Therefore, Candela is not the unit for Temperature.

• Option 2: Density : Kilogram

  Density is a physical quantity defined as mass per unit volume ($\text{Density} = \frac{\text{Mass}}{\text{Volume}}$). The standard SI unit for density is kilograms per cubic meter ($\text{kg/m}^3$). Kilogram (kg) is the SI base unit for mass. Therefore, Kilogram is a unit of mass, not density.

• Option 3: Pressure : Pascal

  Pressure is a physical quantity defined as force per unit area ($\text{Pressure} = \frac{\text{Force}}{\text{Area}}$). The standard SI unit for pressure is the Pascal (Pa). One Pascal is defined as one Newton per square meter ($\text{1 Pa} = \text{1 N/m}^2$). This fits the Quantity : Unit relationship.

• Option 4: Force : Meter

  Force is a physical quantity that describes the interaction which, when unopposed, will change the motion of an object. The standard SI unit for force is the Newton (N). Meter (m) is the SI base unit for length. Therefore, Meter is a unit of length, not force.

Based on the analysis, only the pair 'Pressure : Pascal' maintains the same Quantity : Unit relationship as 'Light : Lumen'.

Comparison of Options

Conclusion on the Related Word Pair

The analogy 'Light : Lumen' represents a physical quantity and its corresponding SI unit. Among the given options, only 'Pressure : Pascal' exhibits this same Quantity : Unit relationship, where Pressure is the quantity and Pascal is its standard SI unit.

Revision Table: Physical Quantities and SI Units

Additional Information on Quantities and Units

In physics and measurement, a physical quantity is a property of a phenomenon, body, or substance that can be quantified. Units of measurement are standard amounts of physical quantities that are used to express multiples or fractions of the quantity.

The International System of Units (SI) is the modern form of the metric system and is the most widely used system of measurement. It defines seven base units and derives other units from these base units. Understanding the standard units for common physical quantities is crucial for solving analogy questions like this one, which test knowledge of fundamental scientific relationships.