Author name: Admin

853. Alcohols are not suitable as diesel engine fuel because the cetane number of alcohols is

A. Very low which prevents their ignition by compression

B. Very high which prevents their ignition by compression

C. Zero

D. None of these

✅ The correct answer is option A.

817. The burnout heat flux in the nucleate boiling regime is not a function of the

A. Liquid density

B. Vapour density

C. Temperature difference

D. Heat of evaporation

✅ The correct answer is option B.

820. Which of the following is the most effective inhibitor of grain growth, when added in small quantity in steel ?

A. Manganese

B. Vanadium

C. Cobalt

D. Copper

✅ The correct answer is option B.

823. Matte smelting is used in the extraction of

A. Lead

B. Zinc

C. Aluminium

D. Copper

✅ The correct answer is option D.

826. Dielectric

A. Is an electrical insulating material

B. Of low resistivity is preferred

C. Should have high thermal conductivity

D. Need not defy the corrosive action of chemicals

✅ The correct answer is option A.

829. The main charge in blast furnace is usually

A. Iron ore & coke

B. Iron ore, coke & air

C. Limestone, coke & iron ore

D. Limestone, sand & iron ore

✅ The correct answer is option C.

831. The transition temperature at which all the ferromagnetic materials become paramagnetic materials is termed as the ‘Curie temperature’. Its value for cobalt is __________ °C.

A. 768

B. 1127

C. 1359

D. 1480

✅ The correct answer is option B.

833. A suitable lubricant used for watches is

A. Metallic soap solution

B. Grease

C. Palm oil

D. Hazel-nut oil

✅ The correct answer is option D.

835. Presence of sulphur in steel reduces the

A. Hardness

B. Grain size

C. Tensile strength

D. Toughness & transverse ductility

✅ The correct answer is option D.

837. Copper deposits are found in India at the following location:

A. Kudremukh

B. Kolar

C. Khetri

D. Ramagundam

✅ The correct answer is option C.