The GATE Grind

GATE 2021 BM – Question 45

Measurements and Control Systems · Measurement Errors and Uncertainty · 2 marks · Multiple choice

An ideal 5 V source drives two series 100 Ω resistors, and voltmeters V1,V2 measure the drop across one. At five times, V1 readings are [2.479,2.483,2.495,2.508,2.511] V and V2 readings [2.465,2.468,2.470,2.472,2.475] V. Which statement is true?

  1. V1 is less accurate; V2 more precise
  2. V1 is more accurate; V2 more precise
  3. V1 is less accurate; V2 less precise
  4. V1 is more accurate; V2 less precise

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (B) V1 is more accurate; V2 more precise

Explanation

The true divider voltage is 2.5 V. V1 mean is about 2.4952 V, closer to truth than V2 mean 2.470 V, so V1 is more accurate. V2 readings have a much smaller spread (.010 V range versus .032 V), so V2 is more precise. These distinguish bias from repeatability. Thus B.

More Measurement Errors and Uncertainty questions

All Measurement Errors and Uncertainty questions →