Insulating materials have the function of___________?
A. preventing a short circuit between conducting wires
B. preventing an open circuit between the voltage source and the load
C. conducting very large currents
D. storing very high currents
The resistance of a conductor varies inversely as___________?
A. length
B. area of cross-section
C. temperature
D. resistivity
The rating of a fuse wire is always expressed in________________?
A. ampere-hours
B. ampere-volts
C. kWh
D. amperes
The unit of resistivity is
A. Ω.
B. Ω – metre.
C. Ω / metre.
D. Ω / m².
A. 2 watts
B. 4 watts
C. 6 watts
D. 12 watts
An electric filament bulb can be worked from____________?
A. D. C. supply only
B. A. C. supply only
C. Battery supply only
D. All above
A rheostat differs from potentiometer in the respect that it_____________?
A. has lower wattage rating
B. has higher wattage rating
C. has large number of turns
D. offers large number of tapg