A. electrons only
B. positive ions only
C. negative ions only
D. positive and negative ions
E. none of the above
Related Mcqs:
- The conduction of electricity, in semiconductors, takes place due to movement of______________?
A. positive ions only
B. negative ions only
C. positive and negative ions
D. electrons and holes - 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 - The conductors have transport phenomena of electrons due to____________?
A. electric field
B. magnetic field
C. electromagnetic field
D. none of the above - The current due to electron flow in conduction band is the hole current in valence band?
A. equal to
B. less than
C. greater than
D. any of the above - Which of the following affect greatly the resistivity of electrical conductors ?
A. Composition
B. Pressure
C. Size
D. Temperature - Which of the following is the poorest conductor of electricity ?
A. Carbon
B. Steel
C. Silver
D. Aluminium - Which of the following materials is the best conductor of electricity ?
A. Tungsten
B. Aluminium
C. Copper
D. Carbon - The coils of D.C. motor starter are wound with wire of_______________?
A. copper
B. kanthal
C. manganin
D. nichrome - Due to which of the following reasons aluminium does not corrode in atmosphere ?
A. Aluminium is a noble metal
B. Atmospheric oxygen can only diffuse very slowly through the oxide layer which is formed on the surface of aluminium
C. No reaction with oxygen occurs ft Any 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
