Sheet no. I

NATIONAL INSTITUTE OF' TECHNOLOGYO KURUKSTIETRATHEORY EXAMINATION

Question Paper

Month and Year of the Examination: Nov/I)ec' 2010

Programme: B.Techo Mechanical Engg. Semester: 7th Semester

Subject: Measuremenll

Course No: MET- 403/lvIE-403 Maximum Marks: 50

Number of Questions to be attempted: 5 Time allowed: 3 Hours

Total No. of Questions: 8 TotalNo. of Pagei used: 2

Unless stated otherwise, the Symbols have their usual meanings in context with the subject.

Assume suitably and state, additional data required, if any.

The candidates, before starting to write the solutions, should please check the Question Paper for

any discrepancy, and also ensure that they have been delivered the question paper ofrightcourse no. and right subject title.

NOTE: Attempt any five questions.

Que I

(a) What are Primary, Secondary and tertiary measurements? Explain with examples. (6)

(b) Difference between Mechanical and Electrical instruments?

Que 2

(a) Distinguish between accuracy and precision. Which of these is more desirab\e during the act

of measurement and why? (4)

(b) Show that, when a step input is applied to a first order system; the output reaches 0.63 of the

step value after time equal to time constant of the system (6)

Que 3

(a) Explain the terms .Confidence limits' and 'Odds' as used statistical analysis of test-data. (5)

(b) State chauvenet's criterion for the rejection of a test-data. (5)

Que 4

Distinguish between (i) Active and Passive transducers (ii) input and output transducers'

Illustrate your answer with suitable examples. (10)

(4)

Sheet no. 2

Que 5

(a) What is a proving ring? How is it used to measure force?

(b) Explain the working of a hydraulic or pneumatic load cell for the measurement of force. |60;

Que 6

Define gauge factor of a resistance strain gauge.

. Show that in a wire resistance strain gauge, the value of gauge factor can be attributed to

the resistance change due to changes in gauge wire length, its cross--sectional area and ,"rirtirity.under what conditions, does the following relation hold good

F= I+2pwhere F is the gauge factor and p is the poission,s ratio. (10)

Que 7

(a) Explain Wheatstone bridge circuit (5)

(b) What is meant by a ballast circuit? How does it differ from a voltage-divider circuit? (5)

Que 8

Write short notes on

(a)Dead time and Dead Zone

(b)Piezo electric transducers

(c)Threshold and resolution

(2)jr,'' (6)

(2)

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