A. increases
B. decreases
C. does not change
Related Mcqs:
- Which of the following affect greatly the resistivity of electrical conductors ?
A. Composition
B. Pressure
C. Size
D. Temperature - High resistivity materials are used in_____________?
A. precision instruments
B. heating elements
C. motor starters
D. incandescent lamps
E. all of the above - On which of the following factors does the resistivity of a material depend ?
A. Resistance of the conductor
B. Area of the conductor section
C. Length of the conductor
D. All of the above - By increasing impurity content in the metal alloy the residual resistivity always_____________?
A. decreases
B. increases
C. remains constant
D. becomes temperature independent - The resistivity of a metal is a function of temperature because_____________?
A. the amplitude of vibration of the atoms varies with temperature
B. the electron density varies with temperature
C. the electron gas density varies with temperature - Low resistivity materials are used in__________?
A. transformer, motor and generator windings
B. transmission and distribution lines
C. house wiring
D. all above applications - Which of the following factors affect resistivity of metals ?
A. Age hardening
B. Alloying
C. Temperature
D. Cold work
E. All of the above - Which of the following materials is preferred for transmitting electrical energy over long distance ?
A. Copper
B. Aluminium
C. Steel reinforced copper
D. Steel reinforced aluminium - Copper, even though costly, finds use in the windings of electrical machines because_____________?
A. copper points offer low contact resistance
B. copper can be easily soldered and welded
E. copper windings are less bulky and the machines become compact
D. all of the above - The converse of hardness is known as______________?
A. malleability
B. toughness
C. softness
D. none of the above
