A. Free electrons
B. Ions
C. Conduction electrons
D. Holes
✅ The correct answer is option D.
Basic Chemical Engineering MCQs
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.
The heat released by cooling one mole of copper from 400 K to room temperature (300 K) is (assume : Cp of copper is 23 J K⁻¹mole⁻¹)
A. 2300 J
B. 4600 J
C. 230 J
D. 2.3 x 106 J
✅ The correct answer is option A.
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.
While the oxy-acetylene flame produces a temperature of 3200°C, the temperature produced by oxy-hydrogen flame is about __________ °C.
A. 1800
B. 2000
C. 2400
D. 3000
✅ The correct answer is option B.
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.
Out of the following, the joint produced by __________ has the lowest strength.
A. Soldering
B. Welding
C. Brazing
D. Rivetting
✅ The correct answer is option A.
Copper deposits are found in India at the following location:
A. Kudremukh
B. Kolar
C. Khetri
D. Ramagundam
✅ The correct answer is option C.
Copper is not present as an alloying constituent in
A. Silicon bronze
B. Constantan
C. Nichrome
D. Delta metal
✅ The correct answer is option C.
The hardness of a grinding wheel is specified by the
A. Alphabetical letter
B. Rockwell hardness number
C. Brinell hardness number
D. None of these
✅ The correct answer is option A.