A. infrared frequencies
B. d.c. and low frequency
C. a.c. and high frequency
D. frequencies having no effect
E. none of the above
Related Mcqs:
- The superconductivity is due to____________?
A. the crystal structure having no atomic vibration at 0°K
B. all electrons interact in the super-conducting state
C. the electrons jump into nucleus at 0°K
D. none of the above - The conductivity of a conductor can be increased by_______________?
A. decreasing its temperature
B. increasing its temperature
C. decreasing its vibration
D. increasing its vibration - An H.R.C. fuse is_______________?
A. a ceramic body having metal and caps
B. a wire of platinum
C. a heavy cross-section of copper or aluminium
D. a ceramic tube having carbon rod inside it - The structure sensitive property of a super conductor is______________?
A. critical magnetic field
B. transition temperature
C. critical current density
D. none of the above - _________ is an example of piezoelectric material?
A. Glass
B. Quartz
C. Corrundum
D. Neoprene - The conductivity of a metal is determined by____________?
A. the electronic concentration and the mobility of the free electrons
B. the number of valence electrons per atom
C. either (A) or (B)
D. none of the above - Carbon resistors are used extensively because they are____________?
A. easy to make
B. compact
C. inexpensive
D. all of the above reasons - Low resistivity materials are used in__________?
A. transformer, motor and generator windings
B. transmission and distribution lines
C. house wiring
D. all above applications - Surface resistance of an insulating material is reduced due to the______________?
A. smoky and dirty atmosphere
B. humidity in the atmosphere
C. both (A) and (b)
D. neither (A) nor (b) - The conductivity of an extrinsic semiconductor with temperature________________?
A. decreases
B. increases
C. remains constant
