Alnico, an alloy used extensively for permanent magnets contains iron, nickel, aluminium and cobalt in the following ratio _____________________?

Related Mcqs:

1. Aluminium bronze contains aluminium and copper in the ratio of___________________?

   A. 50 : 50
   B. 40 : 60
   C. 60 : 40
   D. 10 : 90
   E. 90 : 10

2. Constantant an alloy used in thermocouples is an alloy of __________________?

   A. copper and tin
   B. copper and zinc
   C. copper and iron
   D. copper and nickel
   E. copper and chromium

3. Perminvar alloy having constant permeability is an alloy of________________?

   A. nickel, copper and iron
   B. nickel, copper and zinc
   C. copper, nickel and antimony
   D. iron, zinc and bismuth
   E. antimony, copper and zinc

4. Elinvar, an alloy used in precision instruments, hair springs for watches, etc. contains the following element as principal alloying element__________________?

   A. iron
   B. copper
   C. aluminium
   D. zinc
   E. nickel

5. Cobalt in steel __________________?

   A. improves wear resistance, cuttinability and toughness
   B. refines grain size and produces les tendency to carburisation, improve corrosion and heat resistant proper ties
   C. improves cutting ability and reduce hardenability
   D. gives ductility, toughness, tensile strength and anti corrosion property:
   E. none of the above

6. Which of the following is mostly used used as blast furnace fuel for extracting pig iron from iron ores?

   A. Brown coal
   B. Anthracite coal
   C. Hard coke
   D. Woodchar coal

   Submitted by: Faheem Zaman Dhaunroo

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. An important property of malleable cast iron in comparison to grey cast iron is the high___________________?

   A. compressive strength
   B. ductility
   C. carbon content
   D. hardness
   E. surface finish

9. Paramagnetic alpha iron changes to gamma iron at_______________?

   A. 770°C
   B. 910°C
   C. 1440°C
   D. 1539°C
   E. none of the above

10. White cast iron contains carbon in the form of__________________?

    A. free carbon
    B. graphite
    C. cementite
    D. white carbon
    E. ferrite