Analogy - Verbal and Reasoning

Directions to SolveIn each word of the following questions consists of pair of words bearing a relationship among these, from amongst the alternatives, pick up the pair that best illustrate a similar relationship.
Q1:

Thermometer : Temperature

A Millimeter : Scale

B Length : Breadth

C Solar Energy : Sun

D Cardiograph : Heart rate

ANS:D - Cardiograph : Heart rate

Explanation: As temperature is measured from a thermometer in the same way heart rate is measured with cardiograph.