Which of the following is the poorest conductor of electricity ?
A. Carbon
B. Steel
C. Silver
D. Aluminium
Month: December 2018
Constantan contains_______________?
Constantan contains_______________?
A. silver and tin
B. copper and tungsten
C. tungsten and silver
D. copper and nickel
The structure sensitive property of a super conductor is______________?
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
The transition temperature of mercury is____________?
The transition temperature of mercury is____________?
A. 18.0°K
B. 9.22°K
C. 4.12°K
D. 1.14’K
At transition temperature the value of critical field is____________?
At transition temperature the value of critical field is____________?
A. zero
B. negative real value
C. positive real value
D. complex value
By increasing impurity content in the metal alloy the residual resistivity always_____________?
By increasing impurity content in the metal alloy the residual resistivity always_____________?
A. decreases
B. increases
C. remains constant
D. becomes temperature independent
The coils of D.C. motor starter are wound with wire of_______________?
The coils of D.C. motor starter are wound with wire of_______________?
A. copper
B. kanthal
C. manganin
D. nichrome
An H.R.C. fuse is_______________?
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 conductors have transport phenomena of electrons due to____________?
The conductors have transport phenomena of electrons due to____________?
A. electric field
B. magnetic field
C. electromagnetic field
D. none of the above
Which of the following resistive materials has the lowest temperature co-efficient of resistance ?
Which of the following resistive materials has the lowest temperature co-efficient of resistance ?
A. Nichrome
B. Constantan
C. Kanthal
D. Molybdenum