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Q2. A. With respect to measuring instruments what is the difference between analogue and digital measuring instruments. Explain the working principle of each type.

B. Describe with the aid of simple sketches one analogue and one digital measuring instrument you have used onboard.

Q3. With the aid of sketch describe the main features and principle of operation of a D.C. moving Coil meter. If such a meter is designed to give full scale deflection with 150 Ma, State how it May be adapted; As an ammeter to read up to 150 A; (ii) As a voltmeter to read up to 150 V.; No calculations are required.

Q1.Petroleum vapours are dangerous substances and when mixed with air can be ignited. a) i) sketch an explosimeter or combustion gas indicator which can be used to check the atmosphere of a tank or pumproom.

ii) describe the explosimeter and its operation

iii) state one reason that may cause the explosimeter to give a false reading

b) for flammable mixtures, explain the meaning of the terms lower and upper flammable limits

Q8) With regard to the carriage of crude oil and its associated products:

(a) Sketch an explosimeter suitable for testing pump rooms or tanks, and give a brief description of the operation of this explosimeter (10)

(b) What periodic maintenance or checks are carried out on the P-V Breaker fitted on a tanker ship? (6)

Q3. a) Explain the working of a Megger with the aid of its internal circuit. (12)

b) What safety measures are taken while using a Megger? (4)

Q1. a) Name the factors the resistance of a conductor depends on? (4)

b) Describe three types of resistive strain gauge. (6)

c) Explain the working of a strain gauge used for pressure measurement. (6)

Q4. a) Sketch and describe moving iron and moving coil instruments for measuring current. (10)

b) How the moving iron instrument can be used to measure voltage? (6)

Q5. Write a short note on any two of the following:

a) Voltmeter.

b) Multi-meter.

c) Megger. (16)