41.

42.

43.

44.

45.

46.

Which of the following statements is/are correct regarding ‘turbidity’ in feed water?
(i) It indicates coarse particles which settle down in stationary water.

(ii) It is the suspended insoluble matter

(A) Only (i) (B) Only (ii)

(C) Both (i & ii) (D) None of these

The formation of hard surfaces which resists the heat transfer and clogs the passages
in pipes of boiler is caused by

(A) Calcium bicarbonate (B) Calcium chloride

(C) Calcium sulphate (D) All of the above

Match the various types of feed water treatment methods in Column 1 to that in
Column 2

Column 1 Column 2

(a) Mechanical treatment (i) Lime soda softening

(b) Thermal treatment (ii) Coagulation

(c) Chemical treatment (iii) Uses a series of cation and anion
exchangers

(d) Demineralisation (iv) Deaeration

(A) 8-11, b-i, പി, d-iv (B) a-i, b-ii, പി, d-iv

(©) 8-1, b-iv, പ, d-iii (0) 8-1, b-i, c-iv, d-iii

Which of the following are the favourable conditions for corrosion in boilers?
(A) Low pH, Dissolved 0, & CO, (B) High pH Dissolved O, & CO,
(C) Dissolved O, & CO, Alkali salts (D) All of the above

Which of the following statements is/are correct about hot process phosphate
softening of feed water in boilers?

(i) It is a thermal method of treatment

(ii) It uses trisodium phosphate and caustic soda

(iii) It uses lime and soda ash

(iv) It is a chemical treatment

(A) Only (i & ii) (B) Only (ii & iv)

(C) Only (i & iii) (D) Only (iii & iv)

The corrosion in boilers can be controlled by

(A) Adding alkali salts (B) Addition of ammonia
(C) Removing oxygen (D) All of the above

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