Related Questions

The main function of a muffle in the muffle furnace is to
A Protect the charge from the effects of the products of combustion
B Smooth out temperature inequalities on the combustion side of the muffle wall
C Both A & B
D Neither A nor B
In a muffle furnace, the muffle
A Retards the heat transfer
B Assists in temperature equalisation in the charge
C Permits the use of controlled atmosphere for the protection of stock
D All of the above
silicon carbide refractories have very low
A [

A. Refractoriness (

B. Thermal conductivity

B Resistance to thermal shock
C None of these
একটি ট্রেনের স্থির অবস্থায় দৈর্ঘ্য হলো 100 m। এটি অতি উচ্চ বেগে 80m দৈর্ঘ্যের একটি সুড়ঙ্গের মধ্য দিয়ে যায়। সুড়ঙ্গের দুই প্রান্তে অবস্থিত পর্যবেক্ষকরা লক্ষ করেন যে, একটি মুহূর্তে ট্রেনটির দৈর্ঘ্য ঠিক সুড়ঙ্গের দৈর্ঘ্যের সমান হয়। c এর এককে ট্রেন এর বেগ কত? (A train has a rest length of 100 m. Traveling at a very high velocity, it goes through a tunnel of length 80 m. Observers located at both ends of the tunnel note that at one instant the train appears to exactly fit within the tunnel. What is the velocity of the train expressed in units of c?)
A 0.866 c
B 0.333 c
C 0.5 c
D 0.6 c
Presence of MgO in alumino-silicate refractories __________ its refractoriness.
A Increases
B Lowers
C Does not affect
D Either A or B; depends on its quantity
With increase in the alumina content, the refractoriness of high alumina refractories
A Increases
B Decreases
C Remains same
D May increase or decrease
Silicon carbide refractories are used in the
A Muffle furnace
B Zinc smelting furnace
C Ceramic recuperators
D All of the above
Refractoriness/fusion points of 'superduty' refractories is __________ °C.
A 1520-1630
B 1630-1670
C > 1730
D > 2000
The main raw material for manufacture of silicon carbide refractories is
A Corrundum
B Carborundum
C Bauxite
D Periclase
Faster rate of drying of moulded refractories results in high __________ of refractories.
A Green strength
B Voids
C Shrinkage
D Both B and C

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