A. Silver nitrate
B. Ferric oxide
C. Small particles of iron
D. Silicon-iron
Related Mcqs:
- Commonly used conducting materials are_____________?
A. copper
B. aluminium
C. both (A) and (B)
D. copper and silver
E. platinum and gold - In thermocouples which of the following pairs is commonly used ?
A. Copper-constantan
B. Aluminium-tin
C. Silver-German silver
D. Iron-steel - Which of the following materials is used for making coils of standard resistances ?
A. Copper
B. Nichrome
C. Platinum
D. Manganin - ___________ has the best damping properties?
A. Diamond
B. High speed steel
C. Mild steel
D. Cast iron - A highly conductive material must have___________?
A. highest conductivity
B. lowest temperature co-efficient
C. good mechanical strength
D. good corrosion resistance
E. easy solderable and drawable quality
F. all of the above - At transition temperature the value of critical field is____________?
A. zero
B. negative real value
C. positive real value
D. complex value - Piezoelectric materials serve as a source of ____________ ?
A. resonant waves
B. musical waves
C. microwaves
D. ultrasonic waves - Which of the following are non-conductors of electricity?
A. Non-metal solids except carbon
B. Air and most other gases
C. Pure water and liquids in general except mercury
D. All of the above - Due to which of the following reasons copper and aluminium are not used for heating elements ?
A. Both have great tendency for oxidation
B. Both have low melting point
C. Very large length of wires will be required
D. All of the above - For a hole which of the following statements is incorrect ?
A. Holes can exist in certain semiconductors only
B. Holes can exist in any material including conductors
C. Holes may constitute an electric current
D. Holes can be considered as a net positive charge
