In the following measurement analogy, Ampere is related to Electric current in a particular way. Using the same type of relationship, Fathom is related to which of the following?

Introduction / Context:
This analogy checks understanding of units of measurement and the physical quantities they describe. The pair Ampere and Electric current expresses that ampere is the unit used to measure electric current. We must find the corresponding quantity for the unit fathom. Such questions are common in general science and reasoning exams and require familiarity with basic units.

Given Data / Assumptions:

• Given pair: Ampere : Electric current
• Unknown pair: Fathom : ?
• Options: Depth of Water, Frequency, Sound level, Work or energy.
• We assume standard definitions used in physics and navigation.

Concept / Approach:
Ampere is the SI unit for measuring electric current. Therefore the relation is unit of measurement to physical quantity. In the second pair we are given the name fathom, which is a traditional unit. We must recall what physical quantity it measures, then match it to one of the options. Fathom is notably used in marine contexts, so the correct choice should reflect that.

Step-by-Step Solution:
Step 1: Restate the first relation: Ampere is a unit used to measure the physical quantity called electric current. Step 2: Identify the nature of the relation as "unit of measure to quantity measured". Step 3: Recall the meaning of fathom. A fathom is a unit of length used especially for measuring the depth of water in oceans and seas. Step 4: Check the options. Depth of Water is exactly the quantity for which fathom is used. Frequency is measured in hertz, sound level is measured in decibel, and work or energy is measured in joule or related units. Step 5: Conclude that the correct mapping is Fathom : Depth of Water.

Verification / Alternative check:
To verify, we can construct parallel sentences. "Ampere is the unit of electric current" and "Fathom is the unit of depth of water" have the same structure. No such parallel can be constructed for the other options. Frequency is associated with hertz, sound level with decibel, and work or energy with joule or kilowatt hour. This confirms that depth of water is the only suitable completion of the analogy.

Why Other Options Are Wrong:
Frequency, sound level, and work or energy are all important physical quantities, but none are measured in fathoms. Choosing them would confuse distinct units and quantities. In reasoning questions, one must respect standard physical associations rather than relying on vague thematic similarity. Since the first pair is strictly unit to quantity, only a correct unit to quantity mapping is valid for the second pair.

Common Pitfalls:
Some students may not remember what a fathom is and may guess based on which term sounds most scientific. To avoid this, it is helpful to study and revise lesser known units used in everyday and specialised contexts, such as nautical miles, fathoms, carats, and knots. Even if such units are not part of formal physics syllabi, they often appear in reasoning and general awareness sections.

Final Answer:
The correct completion of the analogy Ampere : Electric current :: Fathom : ? is Depth of Water.