A. smoky and dirty atmosphere
B. humidity in the atmosphere
C. both (A) and (b)
D. neither (A) nor (b)
Related Mcqs:
- Effect of moisture on the insulating materials is to________________?
A. decrease dielectric constant
B. decrease dielectric strength
C. decrease insulation resistance
D. increase dielectric loss
E. all of the above - For a particular material the Hall coefficient was found to be zero. The material is______________?
A. insulator
B. metal
C. intrinsic semiconductor
D. none of the above - The metal having the lowest temperature coefficient of resistance is_________________?
A. gold
B. copper
C. aluminium
D. kanthal - Which of the following resistive materials has the lowest temperature co-efficient of resistance ?
A. Nichrome
B. Constantan
C. Kanthal
D. Molybdenum - Which of the following high resistance materials has the highest operating temperature ?
A. Kanthal
B. Manganin
C. Nichrome
D. Eureka - Substances whose specific resistance abruptly decreases at very low temperature are called___________?
A. insulators
B. conductors
C. semiconductors
D. superconductors - If the resistance of a conductor does not vary in accordance with Ohm’s law it is known as____________?
A. non-linear conductor
B. reverse conductor
C. bad-conductor
D. non-conductor - _________ is an example of piezoelectric material?
A. Glass
B. Quartz
C. Corrundum
D. Neoprene - A good electric contact material should have all of the following properties except_____________?
A. high resistivity
B. high resistance to corrosion
C. good thermal conductivity
D. high melting point - Which of the following material is not a semiconductor ?
A. Silica
B. Germanium
C. Selenium
D. Gallium-arsenide
