Choose the correct word from the given options as one word substitution for the given phrase:
An instrument that records heart's action.
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Cardiograph
A cardiograph is an instrument that records the movements of the heart. It comes from the Greek kardia (heart) + graph (to write, record).
Example: The nurse connected the patient to a cardiograph.
Why the Other Options are Incorrect?
Option 2: Cardiogram — Incorrect. A cardiogram is the record (the graph) produced by a cardiograph, not the instrument: -graph is the instrument, -gram the record.
Example: The doctor studied the cardiogram carefully.
Option 3: Cardiac — Incorrect. Cardiac is an adjective meaning "of the heart"; it is not the name of an instrument.
Example: He was taken to the cardiac ward.
Option 4: Cartography — Incorrect. Cartography is the science or art of making maps; it has nothing to do with the heart.
Example: Satellites have changed modern cartography.