Lime contains about 90% CaO. Percentage CaO present in limestone is about

Question: Case hardening of a material is
[A].

followed by tempering or carburising.

[B].

preceded by its tempering.

[C].

done to get a soft ductile interior with a very hard surface.

[D].

carried out to get extreme hardness in its core.

Answer: Option D

Explanation:

No answer description available for this question.

Question: A balanced draught boiler furnace employs __________ draught fan.
[A].

induced

[B].

forced

[C].

both ‘a’ & ‘b’

[D].

neither ‘a’ nor ‘b’

Answer: Option C

Explanation:

No answer description available for this question.