Recrystallisation temperature can belowered by_________________?

Related Mcqs:

1. At very low temperature, the melting and boiling temperatures become equal. This temperature is____________________?

   A. 373°K
   B. 273.16°K
   C. 303°K
   D. 0°K.
   E. 300°K

2. Ignition timing of a multicylider petrol engine can be adjusted by_________________?

   A. rotating the crank
   B. adjusting the spark plug gap
   C. adjusting ignition coil position
   D. rotating the distributor
   E. delaying the spark by increasing capacitor in ignition circuit

3. Efficiency of rankine cycle can be increased by_________________?

   A. decreasing initial steam pressure and temperature
   B. increasing exhaust pressure
   C. decreasing exhaust pressure
   D. increasing the expansion ratio
   E. increasing number of regenerative heaters

4. In locomotives, the draught is produced by_________________?

   A. chimney
   B. induced draft fan
   C. both combined A. and B.
   D. steam jet draught
   E. none of the above

5. The ability of a material to resist softening at high temperature is known as____________________?

   A. creep
   B. hot tempering
   C. hot hardness
   D. fatigue
   E. superhardening

6. The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to l00°C will _________________?

   A. increase
   B. decrease
   C. remain same
   D. first increase and then decrease
   E. show unpredictable behaviour

7. The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is _______________?

   A. 770°C
   B. 910°C
   C. 1050°C
   D. below recrystallisation temperature
   E. above recrystallization temperature

8. Super conduction by metals is observed in the temperature range of_________________?

   A. below 10°K
   B. above 100°K
   C. around 0°C
   D. around 100°C
   E. above 1000°C

9. Delta iron occurs at temperature of_______________?

   A. room temperature
   B. above melting point
   C. between 1400°C and 1539°C
   D. between 910°C and 1400°C
   E. none of the above

10. Recrystallization temperature is one________________?

    A. at which crystals first start forming from molten metal when it is cooled
    B. at which new spherical crystals first begin to form from the old deformed one when a strained metal is heated
    C. at which change of allotropic form takes place
    D. at which crystals grow bigger in size
    E. at which crystals are destroyed on heating